Show us your home made tools

What in heck do you call those if you were to go lookin?
Vernier slide? It really isn't any different than a set of Vernier calipers and you could probably convert a caliper to do the same. Not hard to make, it just depends on how accurate you require them to be. Digital DROs are so cheap now though, I don't know if it is worth the effort if you start from scratch.