re: Previous missions have...
already brought back parts of the HST, even earlier solar panels (except one Kathy Thornton left in space) and there must exist a scale one version of the HST on Earth (at least its outer hull). So, in a real sense, the HST can be exposed in a museum with instruments that have indeed ben in space and were brought back after every HST repair mission (1993, 1997, 1999, 2002).
I do think the HST should produce a maximum of science until the very end.
Raoul