uh .. I don't think so ..
For the thread starter, is this your "first" MB? If it is, then I highly suggest that first do some research on the particular model that you like to acquire and then window shop on possible candidates for eventual purchase. The C107 450SLC is the long wheelbase version of the R107 450 SL. The "C" meaning that it is a solid roofed coupe, against the "R" which has a demountable solid roof and soft top. The C107 has more legroom for rear passengers however.
Re: Issues ... that really depends on the present physical state of the car that you will buy. As a good practise, it is best to bring along a qualified MB mechanic to thoroughly check the car out before deciding. Fuel consumption is sadly in the single digit category .. my car gets 4 km/litre in a mixed cycle. The M117 powerplant is robust, but be wary of "chain-stretch" .. the valve train has a single chain drive system that is prone to stretching after a long period of time. Check for fuel leaks in the mechanical injection system. Gearbox is a 4 speed automatic, check for shift shock, delayed engagement when shifting from P to R or D, transmission flare (slipping).
I can answer your queries about the car if you have some, but be forewarned that middle aged MB's are a little bit of a challenge to fix right. It would greatly help a lot if you're a DIY guy, if not naman .. I hope you can find a trustworthy MB mechanic that will help you on your project car.
Feel free to ask questions if you have any. Goodluck on your MB!