Two-inch odds & ends and T-rings $5 each shipped
Ok, one is a 2" plug that came with a diagonal I had once upon a time. The other is a two inch visual back of some kind (VB is SOLD). I bought it as an "SCT Back" that fit older Celestrons. It didn't fit my black tube C-8, but I only spent $10 on it, so I kept it. I have used it as an EP holder in a cardboard focuser, but my tube broke and I have since sold all of my 2" EP's. The threads have an outside diameter of 53mm (maybe 52mm, I don't have a caliper).
The T-rings are some I got with a scope (both are sold). One says Canon and has a rotating silver ring that would mesh with some kind of bayonet. It doesn't fit an EOS auto-focus mount, so I am assuming it is a Canon FD mount, but I don't know. The other is also a bayonet mount. It isn't a canon AF or Nikon mount. When I got it it had a faint capital K on it that has since rubbed off in the case. I am assuming it is a Pentax K mount, but I don't know, so don't quote me on it. Both T-rings have removable T-threaded rings held in place with set screws. Maybe you could use them for some kind of project.
The only thing I am sure will fit your needs is the dust plug. If you think you can use it buy it. As-is, no promises, I am just tired of them taking up space in my case. So I will just go $5 each including shipping.
I am raising money to cover the earnest money for a house I have bid on, so I need to do paypal on this one.