Is there such a thing as a mailaway sharpening stone flattening service?

Hi, over the years I have picked up oil stones here and there from flea markets and garage/estate sales. They were pretty out of flat, but since I was new and sharpening small things like chisels, I didn't really care too much. About a year ago I started to notice how it made my strokes uneven due to uneven oil spread and I had enough of it and decided to try and flatten them. It is now one year later and instead of having 3 flattened oil stones, I instead have 3 halfway flattened oil stones and 50 flattened sheets of 60 grit sandpaper.

I am sick of trying to fix these stones and I would much rather someone with better equipment to do it instead. Is there such a thing like that? I know of many mail in services for tools. But whenever I look up sharpening stone flattening services, all I find are lapping plates for sale to flatten water stones. If such a service exists I would be grateful if anyone could recommend me one.