Hi,
I think that we are very lucky to have both K27's and K28s still in existence.
The 20 big 480s and 490s have some 17 still existing!!!
After the D&RGW quit in 1968 running the big locos, eight (8) of nine (9) still existing K36's are actually running or have minor repairs (not needing major restoration like replacing missing parts).
Of the eight K37's still in existence, one is missing a tender, one is running, and one (497) I would consider stored serviceable.
When seeing the C&TS Preservation Study recommending purchase of extra steam locos for a parts source for keeping the rest running, having 5 of ten working locomotives is still amazing.
Doug vV