Yeah, unfortunately I don't have the money, all of my photography is on a budget. I presume by your 'cup-shaped holder' you're referring to
this (which is what I was envisaging having to do anyway, I've seen everything else Grimes can do but I'd never seen that page before somehow). Or maybe I can con the mech guys at work to draw me up a cad model and take it to the cnc machine out the back.
Of course that depends on what shutter I manage to find.
Does the MP4 just have regular #1 sized threads and all? I'm wondering if that will really be big enough, if the Apo Ronar is 90mm across, with a 465/9=52mm iris, shoudn't I be looking for something with roughly the same size, like an Ilex #5 goes to 63.5mm or #4 goes to 44.5mm (iris), with 76mm threads. I don't think that I'll be using too extreme movements so I suppose #1 might work without vignetting (i've got a spare one at least to try out when the lens gets here). Like most things the shutter size I get will probably just depend on whatever I find for cheapest.
The other thing I learned on the weekend is that my Omega 45D has (officially) non-extendable non-(self)-replacable bellows, and I can only get 46cm max film-lensboard out of them before they pop.
Challenge accepted.
My idea is to just buy a new front standard, attach bellows to that, and attach the other end of the bellows to a lensboard (with a giant hole in the centre), making it a true 'add-on' for extending, I should get up to 80cm at least with that rig.
Hopefully that'll save me from having to buy a Sinar/Arca/Toyo45G (like I wanted instead of the Toyo 45D, but couldn't afford).
Or if none of that works, the final use will be to actually use it as an enlarging lens as intended. Had that dream-conversation with my mum yesterday, where one of her friends may be giving away her late husband's darkroom equipment to yours truly. Or maybe there's an 8x10 in her shed too, won't know for a week or two when I get to inspect it all.