hi aggie -
you can get new bellows through camera bellows in the uk. they can be reached through lee filters in la. if your bellows are worn at the corners, and don't have big holes in them, both bostick and sullivan & equinoxphotographic sell a liquid bellows patch that can be painted on the bellows while it is fully extended. i have read that both products work pretty well.
sk grimes does a great job on those shutters. if you were going to use this camera for slow emulsion work, you'll be leaving the shutter open for longer than one second ... it might be nice to have the shutter cleaned &C anyways, so you can shoot film at some point, or luminous liquid emulsion ( asa 100!) but if you use other liquid emulsions they will rate at about asa .5 or 1 depending on the age &C.
you can find plate holders, if you find you need more than 3 ( i have between 6 and 12 ... )- through the nice folks at equinox photographic. they have a bunch of different sizes advertised on their website.
ps. not sure if the lens listed with your new camera will cover 5x7 without that funky extender ... ( my 135 clips the corners off )