I have a special 90 mm Super-Angulon 1:8/90 Sinar wide-angle camera with the len s mounted with a Prontot-Press shutter on a helical focuser in a conical tube di rectly on the rear standard. This is a lovely if somewhat weird camera. As I hav e recently orderd a SV45TE Ebony that I will use with a 150 and a 300 mm lens I have been thinking of getting a Copal 0 or 1 (?) for the 90 mm. To put it simply , can you just order a shutter and screw it together or is it more complicated? Thanks