Hi Mohannad, and welcome to the group!
I also prefer the story of the 1969 car. It sounds much better and it's really unusual: original owner and mechanic since new in one person... it's a fantastic way to know the real history of the car. If it only has 32k miles, no rust, and all original panels (= no accidents), the car should be in very good condition -unless it had been stored during too much time-
About the 1970 car of the dealer: how can they prove that it has only 56k miles, without any record? And about the level of the restoration?
But, after all, the important question is the real state of the car (whatever owners or miles it shows), so maybe your inspector could also check that '70 car. A driving test with both cars could be very interesting for you... and in the end, if you prefer the black color, you could paint the '69 car with the difference ($3.5k)!
Regards,
Albert de la Torre Chavalera
Barcelona (Catalunya/Spain)
Feb.'64 230 SL Euro 113042-10-002432