Sandfish: my dad had a PPK RZM. It had a button magazine release and a 90 degree safety. It was approx 95% condition with some very light muzzle and edge wearing silver. When he passed away, I had to sell it to raise money for my mom. I put it on
www.GunBroker.com for a dollar with no reserve. According to the 2007 Blue Book of Gun Values, an RZM in 100% condition is worth $2500. My dad's sold for $3501!!!!
There have been some faked RZM's out there where unscrupulous types have added the RZM logo (not very well either).
I was surprised to see that your RZM has a heel magazine release. I don't know enough about them to say that that is correct or impossible. It does stick out though as very unusual. You may have an even rarer example that a normally rare RZM. Or....?
We'd love to see some pictures of it posted here!
Good luck! -Steve