For a small musical instrument I need a thin sheet of spruce (1.5mm). Normally I’d just buy a guitar or lute top, but for this one I need the highest quality I can get, with very narrow rings. So my idea is to saw down a blank for a violin top (25mm at its thickest point). I need to do this with as little waste as possible, because a good spruce top can cost 100-300€.
Is there a way I can do this with hand tools?
I don’t know about hand tools, but a skip planer would work. You could use a well tuned hand plane, but that would require a lot or precision and skill.