I can offer an explanation of MC as being Multi Coated. This would suggest to me it is a modern lense as oppposed to "old" lense. They are both Distagon design which is researchable but I don't know enough to tell you anything else.
Thank you , yes of course , it is multi coated term. I couldnt think fast because of price. If I am not wrong these are suspectible for me with being distagon. By the way , I always tried to understand and love distagon but their hasselblad catalog pictures - scene , open air - pissed me off. But interior pictures are better. Grain goes better with bw zeiss shots.
The f4 Zeiss Tele-Tessar 135mm is probably the poorest 35mm lens I own. I'd not be surprised if those Japanese lenses perform better. (The Zeiss Sonnar 135 f2.8 was the top of the line 135mm lens, but I don't have one.)
I did get a Rolleinar 80-200 zoom attached to an SL35E body recently. That Rolleinar performs fantastic. The Rolleinar 80-200 I have was made by Tokina.