Sure,the dark Blue car belongs to a freind of mine in Africa ( car is in France!)and is a 300 SEL 6.3.
When new,the 300SEL 6.3 came equiped with 14x185 VR rated tyres.
These are good for speeds in excess of 200KPH,the top speed of the 6.3 is 230KPH.
So you would not fit H or HR rated tyres on to a car that heavy and can go so fast.
The same applies t the W116 450SEL 6.9.
A very fast heavy car .
But they both came with 14" tyres,and today NO one makes a good tyre in VR rating in 14".
15" wheels have been available from Daimler Benz since at least 1951,and were offered in 1968 as an option for the 6.3 but at that time there were not any 15" VR tyres available.The 15" baroque ( or as the americans call them ...BUNDT) wheels came out in the mid to late 1970's and are very rare and expensive.i would expect to pay at least $1000 each here in Australia.
THe only 15" VR available in 1968-69 were Dunlop or Avon racing tyres and they were too wide.
So....today,we m-100 owners who like a bit of hard driving fit 15" or 16" wheels with yokohama or similar VR or higher rated tyres in the interests of safety.
We always look for early style rims such as Rial,BBS,///AMG ,ATS or similar brands from the late sixties or early 70's.
I have seen ///AMG pentas on the German eBay site and the prices seem to be OK but the problem is getting the germans to bend a little and sell outside germany!.
This is one solution used by ///AMG in 1970 to overvcome the lack of good tyres..[:D]