Yes, it is doable, but you will probably run into a few issues. I ran into them when restoring my original Powerful Gordon.
The unique parts of Powerful Gordon are the smokebox (really the face), all the weights inside, the bottom plate of the running board/chassis assembly (it is dated 2001 and has the old curvey Tomy logo, because it predates the actual redesigned Gordon, and no other Gordon uses this mold - the 2003+ has the new logo and 2002 date while older red running board ones will have the original 1996 date), the weights, motor, and two of the gearbox gears, and the back coupling on the tender. Look for one without chips on the bottom edges of the cylinders, they chip often, two of mine are and a third is cracked and nearly broken off.
The Gordon shell of the day yellows and cracks easily, unfortunately. There are two 2000s Gordon shells, the older PG era one has a poor plastic mix that yellows, and by the time they fixed it the shell had been updated to have the wheel arch lining moved from inside the arches to the actual rim lining
(note the forming crack on the bottom right corner of the PG's cylinder)
Basically, you'll have to be darn lucky in finding a good unyellowed shell or try restoring a yellowed one - that's what I'll be trying to do soon - or use an inaccurate later 2000s one
The flexible engine to coupling tender is the 90s style white with no heat shrink tubing. The tender top can be replaced with a modern unyellowed one. The back coupling looks like this, which is basically unobtainable outside of Powerful Gordon or his original coach.
Overall the problematic things are finding a good condition original bottom plate, an unyellowed replacement body shell, and the original back coupling.