Like most shops there is never enough room. There are 2 solutions.
Enlarge the shop. This is not always practical.
Go up to unused space on the walls or ceiling.
Maybe a third option is a reassement of your shop space. Go over things you dont use very often and move that stuff out to somewhere else.
Nice,
Mine doesn’t quite have the vintage style, but I do have a few signed hardback first editions of Neal Stephenson and others, a few special ones, Iain M Banks from his signings at Foyles in London.
I also have some nerdy ones which have only one or two other users on LibraryThing who have a copy, had to order those from Foyles too.
And some which definitely defy reasonable shelving