Small Study Of And Questions About Early Talers

I was looking at early European Talers focusing on diameter. Four examples were examined to try to figure out if the blanks or planchets were rolled, stamped, and trimmed, or if the blanks or planchets were pre-cut and stamped. The diameter of four coins were measured as follows:
1. top to bottom
2. left to right
3. 10 o'clock to 4 o'clock
4. 8 o'clock to 2 o'clock
The greatest variance of diameter and the orientation are noted below:




Luneburg 1547 waning moon taler Dav 9419 0.57 mm variance top to bottom, 28.61 gm edge is perpendicular to the surface



Saxony 1594 3 brothers taler Dav 9820 0.67 mm variance left to right, 29.26 gm edge is perpendicular to the surface



Austria ND (circa 1626) Leopold and Claudia 2 taler Dav 3331 Hall mint 0.23 mm variance 10 o'clock to 4 o'clock, more than 50 gm one edge is slanted from the reverse to the portrait side to the reverse, not perpendicular



Hungary 1692 hog mouth thaler Dav 3264 0.59mm variance top to bottom, 28.75 gm one edge is slanted from the portrait side to the reverse, not perpendicular

Based on the data, I guess that the 16th century coins were rolled, stamped, and trimmed and the 17th century coins were stamped on pre-cut blanks.

Is this correct?

This guess comes an excellent refence "The Art and Craft of Coin Making" by Denis Cooper. The book is kind of hard to understand, but he says that the punches used to make planchets were conical in that the bottom was wider than the top, allowing the slanted edged blanks to drop from the punch instead having to be forced out.

Also, does anyone know why some of the coins, particularly the 2 taler are almost wavy?