John, thats pretty much the case for the folding plate cameras, like the black leather covered wood or metal cameras, such as the Bergheil, Vag, Arvus, Recomar ect ect, the various makers list is long. they take the metal glass plate holders that with a metal film sheath inserted convert them to take the nominal size film, which is in fact as you say, smaller than what the glass plate was.
however, so far as i have ever seen and all the ones i have, with the whole plate (and other original plate size film from pre 1900's) the cameras are generaly those of the veiw/field camera design (there are others too) and they use the wooden bookform film holders.
these type dont need (use) a metal film sheath at all (likely it would be in the way), the film fits in precicly where the glass plate originaly did (cant fall through because it sits on the same lip as the glass did) and a flat board is placed behind the film (if viewed from the front), on top as you have the book holder open, load the film, and then the spacer board to make up the thickness of the origial glass plate. many of the old cameras using wooden bookform holders often arrive with a board of some sort in them already (indicating the camera had at one time in the past been used with normal film), sometimes with notes or some other things stuck to them indicating the date they were last used, which is often pre-war is some instances. so for these film replacements the film simply needs to be the original size, just as it was for glass plate...unlike the 6.5x9, 9x12, 10x15 so on and so on glass plate film replacements of other formats...