I think it would work fine as a troubleshooting tool. Northern Tool, for one sells gages in many sizes and ranges... . and they have enough resolution to read what we need. I'm sure most of the industrial outfits such as Grainger and McMaster Carr also sell agages that would work fine.
As a matter of fact I have been considering making one up for troubleshooting for myself... and for my son to use at his shop.
Jay