Douglas -- if you carry that logic (re: "Call me crazy but there's a side to me that just hates to see one more Pagoda vanish forever.") to it's end, then nearly all the pagoda's ever built would still be out there and being driven and in reasonable condition. If that were the case then spare parts for them wouldn't be rare either... and in a nut-shell, they would have much lower value than they currently have... so much lower in fact that the economics to keep them in reasonable mechanical and cosmetic condition would force fewer owners to spend the $$ to do so... hence letting them rot in some barn or spare lot, or selling them for parts at the local dismantler/junk-yard.
So... at the core of nostalgia for cars (whatever car, or house, for that matter) is an economic decision... the greater the cost to satisfy the nostalgic desire, the fewer the number of people with the means to do so. Given the means, the nostaligic buyer will still (normally) seek the best condition car for the outlay, since to do otherwise is just throwing away some of the means to improve upon the condition.
Granted, there are those that do so... a fool and his money are soon parted... there's a sucker born every second, ... and similar... but those are the abnormal condition. ... not necessarily the exception, mind you, but non-normal. I recall the 90's sudden craze for the 60's Mustangs.. prices skyed almost overnight... and kept rising. More Mustangs were "restored" than you can shake a stick at... spare parts and "OEM" manufactured parts that were previously unavailable appeared almost overnight at reasonable prices. A friend of mine at work had been driving his Boss Mustang since he'd originally purchased it.. it needed paint, upholstery, various other odds/ends, but he'ed kept the mechanics in reliable driving condition as his "work cummunter" ... it was more economic for him to keep it that way than buying some other used car (with some "muscle" to replace it)... and the used car prices for his car prior to the sudden craze were not high enough to find a replacement commuter with "muscle" (or the known & trusted mechanical reliability). When the craze hit he watched the prices rising... he eventually had unsolicited offers for it, and took it to a Mustang "show" event one Sunday... just to see if he would get some "unreasonably high" offers. He sold it that Sunday "as is" for $15k. A year earlier he couldn't have gotten $2k for it!.
Point is only that sometimes a sudden craze occurs, usually short-lived (on the order of 5 years or even less) when demand accelerates abnormally... and then the enterprising among us find all those old examples that can be put back together (or put a shiny coat of paint and some new uphostery and a underbody steam-cleaning) and turn it for a profit. Supply increases, prices stabilize, and the craze / fad passes and demand wanes once again, prices fall, and the least worthy examples end up back in the junk-yard or under the crusher.
Seems to me that if a person wants to spend $30-$35k or more on a 280SL 4-speed they'ed get more value for their time/money and enjoyment by buying one that's already closer in real value to the $30-$35k limit than one further from it. If they're seeking a hobby to restore a car of some vintage/type.... and know what they're getting into as a hobby, but without all the tools and equipment necessary to make the hobby effectual, then the hobby is the desire, and the car's just a means to effect the hobby.. it still costs parts, tools, equipment, and vended labor from specialists here and there... i.e. sufficient economic means and perseverence are the pre-requisites... skills can be learned (by trial/ error or from some other professional or experienced body).
The single biggest failing for the hobby seeker who wants to restore some vehicle or another is a lack of knowledge of the total costs required, therefore getting into it before realizing they don't have the means... the 2nd biggest failing is lack of time or perseverence over time.
So... I think the question on the car in the picture is whether anybody that hasn't personally inspected the car in detail, and who isn't already well equipped and experienced enough to recognize the actual costs and efforts involved in restoring it can make a rational assessment. I think not. As a restoration project it's a minimum of $30k - $35k (at best, imo)... if a well done (body-off) restoration, including all mechanicals, the costs would approach $40-$45k, and value would be upwards of $50k - $65k (4-speed, numbers matching, no rust remaining). In other words, the real value of the labor and time used in restoration is on the order of $10k - $15k. Assuming and considering spare time is of no other value, "earning" the equivalent of a month or two's salery over the course of the year or two (or 5?) it would take in dedicated spare time effort for a body-off restoration (a-la bpBossels restoration effort) is not a minor undertaking... somewhere in the range of 1/12th to 1/24th a years salery (or less if in the upper income brackets, or if it takes more time than 1-2 years of spare time). As always, the question ultimately answered is whether that is enough incentive to continue the effort after the newness of the experience wears off, and whether there are other liesure or spare time pursuits with greater incentives or demands(wive's, children, or significant other's demands on time/effort for just one example). It could easily be argued that the expenditure of the spare time on restoration could be better spent to far greater economic and ultimate life advantage (in 10's of multiples of the $10k-$15k) by expending it at one's saleried place of employment and this would especially be the case for the younger ones who're starting or in mid-career... assuming one likes their job, that is... and isn't just an 9-5 clock-watcher.
Sorry for the length of this, but the issue you raise is not without merit for discussion and dissection. It is a common underlying theme on this forum. If one doesn't have the means and perseverence, then the pursuit of restoration and especially of a near basket-case is that of a fool.... since they'll pour significant money into the effort without being able to carry it thru... ending up with something of probably no greater value (and possibly even less) than they started with, but after a loss of time and money expended to no satisfying ends.
