I got this from the junk bin at a local store the other day.
I didn't even know Mamiya made 35mm SLR cameras so it was a bit of a surprise. After looking it up I've learned that this particular zoom lens is somewhat rare. It has a magnification ring that acts like extension tubes. Kinda weird. The only problem is grungy light seals. The clerk at the store put new batteries in it for me and the final bill, including batteries, was 1,000 yen or about US$10! Such a deal. Soon I'll be running some film thru it.