For the moment the two companies you mentioned ARE the only game in town. For over 60 years the only maker of carbide tools supplied the craft...that has been interrupted by death and taxes. Hopefully it will be resurrected soon. The style of checkering is called "flat top". To find the lines per inch use a ruler and count the lines in one inch! To find the angle...a protractor is great. It is not hard to do IF you are patient and read a lot before you start. Monte Kennedy's book is where I started and still pull it out to refresh my knowledge from time to time.
The checkering done on that stock was done by a riffler file. Problably a home made file with 75 degree sides and a small flat on the bottom. All surfaces cut.
