[Arran]

The rubber parts are available from a few places I think, but why do you think you need knobs? The knobs on your 38-10 look correct to me, some of those sets had a bar shaped knob for the bandswitch but the photos I have seen of the 38-10T have the same knobs as your set. One point though, as you are probably aware the front panel on the 38-10T had a faux wood grain finish, and the outer ring of the dial bezel was black. I don't know why but a lot of restorers seem to have this impulse to polish up dial bezels for really no reason at all, most were antiqued at the factory, one of the few exceptions being some 1936-37 RCA models.
Regards
Arran