These model years / designs are very different from each other and the doors are not interchangeable.
1996 and newer will fit.
Doors from a 1977-79 Caprice or Impala would be interchangeable.
The Nissan Quest starter is the same.
Its in the fuse box under the dash with the other fuses.
In the relay box in the engine compartment with the other relays.
The speedometer is part of the instrument cluster, and is fused with the other instruments.
It would be in the relay box with the other relays.
Yes, the doors and windshield interchange as follows: 1984-1991 windshield interchangeable. 1984-1987 2 door LWB doors interchangeable 1984-1987 4 door doors interchangeable 1988-1991 4 door doors interchangeable 1989 SWB 2-door doors interchangeable with 1988-1991 4-door front doors and rear barn doors. note: pre-1988 4-door doors will fit 1988+ mostly, but the lock mechanism has a different retaining hole. but the newer locks can be re-keyed to match the older keys, and vice versa. you just can't put the whole lock from one into the other. There were also 5 distinct hinge redesigns which make door fitment slightly different with different years - for example the hinges from a 1986 would swing the doors too wide on a 1991 and allow little kinks from the interfering sheet metal.
1994 1995 1997 1998 1999
No other Chevrolet doors will interchange with Celebrity doors. Some other "A" body doors may fit but the lines and mouldings don't line up with the Celebrity body lines. I understand that Pontiac 6000 doors come the closest.
The speedometer is part of the instrument cluster, and is fused with the other instruments.