Engraving on leather does beautifully - just be sure to use vegetable tanned leather (any leather supplier worth their salt will know how it’s tanned). It takes very little power to get a nice engrave.
I would suggest doing the ageing first - then using masking before you engrave
There is also a parchment called Pergamenata that is a nice heavy weight that takes engraving beautifully, but it’s much lighter weight so leather will be a hardier material (I’d totally recommend Perg if you were going to frame it, less so if you want it to be touchable)
There are a few posts on here where folks have made swords - including the hilts by cutting many (many) circles and then gluing them together - you could make your scroll handles the same way