Hello
The short answer to your question is No. Once a locomotive is "retired" it is striken from the roster and disposed of. However locomotives can be "Stored" and returned to service in a similar process you describe.
This store and return to service process occurred for the Big Boys from about 1957 through 1959. 8 where kept in storage for a potential upsurge in traffic after that date. But the need for them never materialsised The 8 that were kept after 1959 were finally retired in 1962 and are the same 8 that now reside in railroad museums across the country
If you watch the railroad Film "Last of the Giants" which was made by the UP RR all the footage in that film is of the big boys when they were working locomotive crunches.
As for your diarama, My best suggestion would be to arrange several paralell tracks, and have several big boys sitting, have all their smoke box doors open, any covers and grates open to, You will want to cut the coal load out and model the rest of the coal bunker because the tenders would be empty, and you would want several teams of men inspecting parts, checking things and doing simple repairs/prep work. and a Diesle switcher on hand to pull the loco down to the engine service area so the coal can be put in the tender, Wather in both the boiler and tender, and a fire built. Also all the lubrication woints would need thoroughly checked.
Hope I have been of help.
Useful resources.
The "Last of the Giants Series" and the "Union Pacific Big Boy Collection" both are available from Pentrex.
www.Pentrex.com
Master of Big Sky Blue :)
Thank YOU !!!!!!!!!!!!!!!!
That was very Good info on the subject I asked about !
Take Care,
Russ