Hi Benny,
Besides Bruce's suggestions, you'll also need to modify a caliper to measure the riser height. You can also make templates to measure the undercutting and overcutting and check the angles of the strike wall and opposite wall. You'll also can make a simple tool to measure a crucial part of the bore for a specific measurement which can give you an indication of the general taper. Then there are other visual confirmations you can make by comparing profiles off certain components from various perspective angles.
There are a lot of things for comparison to look at, embouchure hole dimensions are but a small part of what you need to measure to explore a headjoints specs for performance. You can't buy most of the tools either, they need to be made.
I would disagree with Bruce that the strike edge needs to be sharp (relatively speaking) That is a myth and headjoint makers control the amount of sharpness to control a particular tonal characteristic.
My NAPBIRT headjoint class covers all of this. I will be in Reno next weekend presenting it again as a hands on clinic for preregistered NAPBIRT members. However, if you are not a member Benny but happen to be in the area, I'd be happy to take time to show you the tools and how to use them, make them, and give you an overview of what affects what in headjoints.
Joe B