Can a seized aluminum motorcycle engine be disassembled without further damage?

I am having a hard time looking for a rebuilt crate engine for my 1982 Honda silverwing gl500i.

I think I’ll need do disassemble the engine to see which parts I need if I cannot find a new engine.

I have searched many websites and have had no luck, only to find parts sold separately.

Were might I find a place that would be useful?