That...is a good question.
MB sells the replacement starter # 003 151 07 01 88 for all years 616 and 617 motors. That number replaces a number of different previous numbers.
Bosch still sells the replacements under 2 numbers SR 61x and SR 67x. The first fits the early years and the last the newer years as per your description. I have used the SR 67x for years for all motors thinking I was using the higher output starter.
Recently we had a 80 model 240D that over two years we put a SR 67x starter on it every six months almost to the day. The problem on each was the starter stayed engaged and the person drove it till it destroyed itself. We got with Bosch as we are a Bosch Service Center and they said at first that the staters were interchangeable. On further research an engineering document was found that indicated that certain of the cores used for SR 61xs would need a machine operation in the mountng area to be interchanged. We replaced the starter ring gear the last time and used the SR 61x and I think its been over six months.
The MB numbers replaces all, so from them one size does fit all.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician