They are both equivalent. Scratch-built is perfectly cromulant.
My father used to talk about 'Scratch-building' his WWII dioramas and model vehicles/tanks. While you could use a phrase like 'Scratch-cooked' rather than cooking from scratch, I've never heard but someone would not think the former meant something different to the latter.
My father used to talk about 'Scratch-building' his WWII dioramas and model vehicles/tanks. While you could use a phrase like 'Scratch-cooked' rather than cooking from scratch, I've never heard but someone would not think the former meant something different to the latter.