If you were the world leader in antique maps, you’d make a pile of money from that niche. Being able to search for authentic maps for anywhere in world, sorted

If you were the world leader in antique maps, you’d make a pile of money from that niche. Being able to search for authentic maps for anywhere in world, sorted by time period — that would be a big hit in certain circles. You could ask who would buy first edition printed books — but that’s also a pretty large niche with lots of passionate customers. For example, I’d be interested in old aviation charts or wartime maps from World War II or the US Civil War/etc.