Excuse this noobie question but I have a 2009 and a 1992 (and many a 3rd bike soon). Are the wheels the same? Can you just swap front or rear wheels from a 1992 and a 2009? Doing it just for appearance as the 2009 will look best with white wheels (I think) and the 1992 which will become red and black over the next couple months and will look better with black wheels (or dark silver metallic - time for the rattle can?)

Brake discs: Should they be swapped with the wheels, removed from the wheels and switched so they stay on the same bike or get new brake discs? Should I replace brake pads at the same time or just do it since everything is taken apart anyway?

FYI: When I do the swaps, I plan to replace the sprockets and chains. And any used tires will be replaced with stock size tires so they fit all the goodies like the rear huggers.

no, they aren't the same.  different colors means different parts numbers.  but they will directly swap.  when you swap, you can keep the sprocket carriers on the bike they came from, so as long as they don't have any shark teeth you would generally be fine there.

Thanks. That's what I wanted to know. I was meaning physically the same, not cosmetically, and you answered that for me.
I can swap wheels but keep the sprocket on the same bike because it should stay with the same chain (or put on new sprockets and chain).
This will give me a reason to learn about wheels & bearings & taking wheels off and on.
I have spare white's coming in. I'll clean them up, put in new bearings (just to be safe and to learn how to do it) and put them on the 2009. Then take the black wheels from the 2009 and put them on the 1992. I'll remember what you said about the sprockets.
Thanks again.

The 92's have different front brakes calipers, not sure if the rotors are any different.

Good advice. I'll plan to keep the same rotor with the same bike. Probably best since the pads would have worn to  the rotor.
So sprockets and rotors stay with the bike.
Wheel & axle will get swapped as a set.
The '92 will probably get new chain & sprockets and might as well learn to do brake pads, too. I don't know how old the pads are.