>>4068341There's more to it than just a taller window. The magazines have darkslides so the pressure plate is retractable. In order to have the retracting pressure plate re-register precisely, the pressure plate has alignment pins and the film rails corresponding sockets. The alignment is needed for the data back, which also includes a mask under the film gate for the printout area. The pins also aligned the top and bottom edges of the film. There's also the integrated hotshoe.
Plus all the usual space mods like non-outgassing lubricants and non-flammable component and coating substitutes.
