Claybyrd,
I got them from Dr. Ken Howell's _Designing and Forming Custom Cartridges for Rifles and Handguns_, ISBN 0-9643623-0-9, one of the best $60.00 investments I've ever made. Your local Carnegie library should be able to get it for you on interlibrary loan.
I know nothing of the Davis, except that it a shortened (1.6") .348 case with a sharp shoulder. The case displaces 98 grains of water.
Google will get you some data on the old Werndl gun and cartridge. I make mine from .348, though the rim is a tad bashful. The case displaces 127 grains of water, and is listed as the Gras 11x59R.
Regards from Grayest California,
Ross