In the early 70s I owned both a Mamiya C33 and a Koni Omega Flex. My parents bought me the Mamiya, but I traded it in for for a Koni Omega Flex because of the 6X7 format, used Koni Press backs and it had a dark slide so I could change lens in the field. I used for many years and found it to be reliable with good lens. I don't if Koni Omega Flex's are available and what the repair outlook is, but I would give it a look.