Hello jgfox,
I guess your sorta a "black sheep" here with your (W107) SL and all these (W113) 230, 250 and 280 SLs ! You may want to move to the Vintage category on the Mercedes Club site where the information can be a little more relevant.
Welcome anyway! These seals install the same as in the W113 SLs. The secret is not to try sliding them in place. Push one side of the seal into the channel then use a blunt flat tool to insert the other side a few inches at a time. A wooden paint stir, possibly ice scrapper, butter knife etc. can work.
Joe Alexander
Blacklick, Ohio