Indeed, I'm an f22 man when I can be...

Check my logic: all distances relative to the reference flat on the camera... the ground glass is at ~5.1mm. The back of a Fidelity film carrier is at ~4.8mm. The film is 0.15mm thick, and the emulsion faces the lens. The emulsion is therefore 5.1 - (4.8 - 0.15) = 0.45mm closer to the lens than it should be, I think.

(the measurements were miked as the thickness of the frame and standoffs supporting the glass. The outer side of the carrier is more worn; it gets a lot more sliding past it over the years than the inside.)

I'd have a job taking half a millimetre off the original ground glass carrier casting, but I might investigate machining some paxolin to make a new one.

Fortunately the sixty or so pictures I took last week were mostly in bright sunlight... my scanner has died but the first impressions are hopeful.