I found it rather difficult to resist commenting on your question in regards to the Mamiya RZ67. Over the course of over 40 years making photographs in many different countries around the world and using a fairly broad array of cameras, without a shadow of doubt, the Mamiya RZ67 has always been my favorite camera. It is exceptionally well built, most of the lenses are excellent and working with the 6x7 format is a wonderful compromise between 35 mm and view cameras. Indeed, close to 75% of photographs on my website were made with this wonderful camera.
Enjoy it to the max.
www.eugenehjohnson.com