The look of the house is rustic, knotty pine, panel boards running up the walls exposed beams, even though the cabs are made of (cab grade ply) everything looks right to me, ranch style look.
The carcass appears to be in good shape if it is solid there are only a couple of exposed sides to veneer. Simplest, a solid color paint and new doors could work.
Next selection you could take one of the small sections out and see how difficult it would be to remove the face frame from the carcass, (those new little multimasters are killer for this type of job). If the damage and time are minimal rebuild one at a time from there. The thing is you have so much interlocking trim, it'll be like trying to take and keep hamburger hill.
For me, the removal process is going to be challenging and time consuming there's wood interlocking everywhere. I would build new upper cabs ply carcass, (the few exposed surfaces can be veneered), solid face frames and doors. When done I'd remove the existing uppers as gently as possible and store them for resale when the lowers were available.
Never bite the hand that looks dirty!
The more you know the more you're worth