I run all my engines but I do have a Mint 6464-200 PRR Boxcar that has never seen the rails, also a 6447 PRR Caboose in the same condition. I have multiples of the -200 and many 6417's so I see no need to run those particuler ones.
The black 2332 GG1 gets run as does the JLC PC GG1, also the '64 773. No mercy there.