@Rmiked if you want to go further down the measuring rabbit hole do a search on the 1911addicts and 1911forums on how to properly measure the frame and slide on a 1911. You’ll learn about several different techniques and tools that smiths use to take all the measurements they need to make sure they end up with a quality fit.
ETA: or just spend some time browsing the gunsmithing subforum on either forum. While there aren’t as many Smith’s posting in the past there is still a lot of good info and answers to questions you didn’t know you had on those sites.