Alfred,
I answered Scott--offline when he queried. The reality is I do not have, and have never had any experience with the 2-piece wheel covers, or "hub caps" and "beauty rings" that they are often called. So I'm only guessing.
I
think that wheels that accomodate these are a different pressing than more modern wheels; they don't have the bulges, etc. that make fitting these things easy. As Hauser points out, some drilling is necessary. Goodness, if you find a set and start drilling, make sure you get it all right. You've got one chance. They'll look very goofy if you don't, particularly as you are driving...
I believe that MB went to the one piece wheel covers somewhere at or around the end of 250SL and beginning of 280SL production 1967-1968? Since these light weight wheels originated on
diesel sedans 5 years after production of the W113's ended you can be sure they are of the later style.
Aside from this "new" use for W113 owners (driving up the price and the scarcity) Jim Villers pointed out that vintage 190SL racers have used them for some time. So, somebody must have figured out a good way of fitting 2-piece 190SL wheel covers. You can't really tell much from a photo as to what kind of wheels are fitted.
Here's a close up of one of the wheels; there is a before and after. The before shows what you are likely to find as I did, at a junkyard. Then I had it refinished and POWDER COATING (sorry thelews but paint does not belong on wheels). The wheels in their natural state will have a dashed silver line around the bolt pattern if 5.5"; and a solid silver line around the bolt pattern if 6.0"; that's the easy way to tell them apart at a junkyard. You can see that the before photo shows the solid line indicating a 6" wheel.
Here's the "Before" of a 6" wheel in junkyard condition.
Here's the "After"
of the same wheel, powder coated.
BTW, I offered a set of two wheels
refinished for sale as you see, at my cost a year or two ago. Only ONE group member inquired in a timely fashion and bought them. No, I don't make a market in these wheels and I have no more sources. I started looking the day I got back from PUB 2005, and it took me until May 2007 to complete the set. I had picked up a few; had them refinished, and was looking for more when I came across a full set of 4. That made my other 2 available, and those are what I sold. I then took my 5th 6" wheel, destined for the spare, and as a gesture,
traded it to another member for a 5.5". He needed just one more to complete a set. Nothing wrong with the 5.5" in the trunk. It's all about networking people!
ONE LAST THING: as Gernold (SL-Tech) pointed out to me, you really should have
special wheel cover clips to prevent marring the soft aluminum of the wheels. The
standard clip is all metal. There is another clip (Gernold has them) that has a soft cushion on it so the wheel is not scratched when you take off and put on the wheel covers.