I’ve got hundreds of tools (in hundreds of different locations around my house and workshop, but that’s a different story), so allen (hex) keys and screwdrivers aren’t a problem, but gauges aren’t something I use so I looked at all the options for guitar adjustments. I came to the conclusion that for now I probably wouldn’t need to be so exact so I bought one of these;
https://smile.amazon.co.uk/gp/product/B013WJCXQO/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
For only a few quid/bucks/euros they make it much easier to get some gaps right (enough).