Trust me I didn't take it. He was well compensated for his loss. He was quite happy that I was young and would use it. He told me to send him images from the M6/Jupiter 8 combo.
I was waiting for the shoe to drop and the next post would be an offer to take this bad Karma camera and properly exorcise the Karma, converting it to a proper owner who gets good Karma from removing it from your now tainted hands, for a fee on your part. ;-)
Actually, I try to pay a reasonable price and be fair, that said, if someone has a price in mind and is happy with the deal, plus any time you buy anything used you run some risk of a repair situation. Am assuming you did not block the gentleman's wheel chair and hold his cat for ransom to twist his arm to sell. I have given away some good cameras, hopefully to good hands, and sometimes to great hands, made easier by the knowledge that the camera was going to good use and I was not going to use it.
Use what ever lens you want, but I agree the glass and light make the image, so any sound box with a proper shutter and reasonable exposure should give similar results. The ease of use of some cameras is highly personal, and will affect your comfort in use. A good price also affects your comfort as well. ;-)
And, you probably can pass along your FSU glass to the appropriate home when you are through with it.
Regards, John