For what I know, #8 is not a part source for shays 12 and 14. #8 is not being slowly disassembled to keep the others going. Guys that used to run 8 joked that it donated parts to the right of way as it went along, but not to other engines. Rick Steele, any comments?
8 is big, but not too big. There are no curves or bridges that restrict the use of #8 on the GLR.
#8 is not in service for the same reason that 44 is not. It needs a lot of work. To repeat Josh, it will need to wait for 44 to be completed.