I follow you on the oil tanning.
The issue I'm having is that my sporran has a touch of red to it's brown. I just didn't see any belts that color, so I was going to look else where.

However, if someone told me I could use a sporran belt that went with the color of brown on my sporran, instead of having to exactly match, I might be happier. I don't know if that is OK up on the snob level though...

Thankfully, I have most of the basic leather working tools that I would need if I have to build my own belt from scratch.