Are the -100's, -200's, or 250's viable for service anymore or is engine support dead except for the -500's now?
Engines on the -250 model are the same as on the -500. IE: RB.211-524B402.
-200's are equipped with the -524B02, no serviceable engines available that I know of, except what is installed on the wing of the few remaining.
This is a distinct problem for the -200F type.
However, -524B402 engines can be installed, but...the number two position requires mods to the titanium ring.
-100's are equipped the the -22B varient, few serviceable engines left available. As with the -200, -524B402 engines can be installed, with expensive mods.
The L1011 will be in service for charter ops until sufficient numbers of the B767-300 are available, at prices that many operators can afford....figure three years, tops.
The -500 type, awhile longer.