Hello Brian - Information from the Technical Articles on the site and other old info off Yahoo!:
"Starting with production of the 230SL in 1963 to the 280SL in 1969 the solid one-piece bezel & red lens unit. According to Laurence Meredith (Orginal Mercedes SL Restorers Guide see Page #68) Amber indicator lenses replaced red ones for all markets in February 1969.
Frank Mallory, a noted Mercedes Benz expert, states that the change took place in 1970. There were three different types of 230 SL taillights. The regular ones were all-red with clear back-up lenses. The French ones have orange (amber) back-up lights instead of clear ones. The Italian (and possibly for Australia) have clear back-up lights like the original ones but orange (amber) turnsignal lights. You can find all three different types on eBay from time to time."
As for the headlights: (old info off Yahoo!) "US 113 cars had amber & white vs. pure amber running light in the headlight. The small amber has the code AN while the large amber has the code AJ. There are differences in the lights so they are only interchangable with some work, and only in pairs. They all fit the same however.
I believe that the AC lights are the earliest, used on 230/250/280 to chassis number 5607, which was early in '69 production year. The AN lights were used on 280's from chassis 5607 to 11947, and the AJ for the remainder of the production run. I have not had all three in my possession at one time, but the differences between all of them have to do with the number of bulbs; colors; and wattages for the parking/directionals with the sealed beam headlight being the same for all.
The biggest difference is in the AJ which contains an additional power "jack" to connect the side marker lamps which had changed from side marker reflectors and now needed power due to DOT regulations. All assemblies are still available; however they have vastly different prices. The AC is about $285; the AN about $340; and the AJ about $220. Go figure.
My new AJ's were made in the Czech Republic and were ALL plastic, including the chrome. NOT NOS! More important is the socket-back which contains the reflectors and the wiring for the directionals and parking lamps; the only one still available is the one for the AJ. Note this is not included in the above prices and is a separate part.
When I needed new headlamp assemblies, I opted for the AJ because of price, but more because my socket backs were shot (no chrome left on
the reflectors) and could not get any new ones for my original AN assemblies. Socket backs are definitely NOT interchangable. So if you have AJ's, I'd suggest only replacing them with AJ's else you need to do a bunch of wiring to accomodate your side markers and you'll have to do something about those socket backs."
So on your car, solid red tail lights appear to be appropriate/original. Personally I like the euro headlights and the orange rear lights on my 1969 280 SL. But many people really favor the solid red tail lights (NLA other than in -expensive- reproduction).
