Dismantling an old piano

I’m trying to dismantle an old piano, and I would like to do it without damaging the individual parts or pieces of timber (for sentimental reasons – may use it in other projects).

I’ve screwed out and removed all I can but I’ve gotten to the point where I want to remove the keyboard section from the main frame. There were two screws on each side apparently holding this on, but even after unscrewing these it remains stuck fast. I assume there is some kind of glued joints or dowels somehow keeping it together.

Is there a handy way of removing this while minimising the damage to the timber? I’ve managed to hammer a sharp knife in between, but that will only go down an inch or so, is very narrow, and won’t do any good in prying them apart (it’ll bend then break quite easily), but it shows something could go in there if it was as thin but stronger and broader.

Is there a tool or something, maybe similar to a chisel but a lot thinner that is used for prying joints apart while minimising the damage to the actual timber?

The parts of the surrounding frame itself is just as stuck together so I’m assuming something similar is going on there, but the main thing is this keyboard section so I can then put all the parts away…