BandeauRouge Loc: usa

does anyone have a recommendation for getting a tripod for it? I have the manual that came with the camera and well it shows a tiny metal thing similar to the crappy metal music stand we had in middle school... simple screw in rod..

but ive seen period photos showing nicer tripods on them,, but the lack of a second hole for a movie mount locking pin has me cautious as that pin would be located directly ON the battery cover door.

CHG_CANON Loc: the Windy City

I'd look at an arca-swiss quick release 'plate' to attach to the body and then clamps to that plate. The Mamiya 'spacers' all seem to give space to allow the film back and / or lenses to be attached / detached with the tripod adapter attached. Not having such a body to measure with a ruler, look to see of something like the RRS B82 plate might be a starter solution. It has a 1/4"-20 threaded screw on a plate 2.6-in length plate with a anti-twist flange. Is 2.6-inches long enough for the raised flange to reach one of the edges of the body to 'lock' the plate? If yes, then look at any of the various screw or lever clamps to 'grab' that dove-tail plate for attachment to a tripod.

There are generic plates without the anti-twist flange. These are just a twist problem waiting to be a frustrating failure.

There's also the RRS universal foot L85 is 3.6-inches with the 1/4"-20 screw. This too has an anti-twist flange that is probably the size needed for the Mamiya 654 to reach any of the four sides of the bottom of the camera from the tripod mount female screw socket.

The real ease-of-use question is whether you should 'stack' a few plates / clamps for 'space' under the camera body to easily reach and attach the clamp to the body and tripod, also giving space to allow for all camera operations and add / remove lenses and film backs.