If you haven’t already, you should come up with a logo or some way to mark them as made by you. When you become a famous pipe carver it’d be cool knowing these were your first pipes.
Yeah I've read all of that. There are very limited resources that I have found on the matter. Every cutter/supplier also seems to have there own sizing and grading scale. Prices seem to be higher based on availability "due to aging process". You can get good to great quality from different countries. Plateau is better "fire" grain. For rusticated pipes that doesn't matter. Hence the question about preferred briars, if known (I know it's not always disclosed by makers).I think it's more the grading than where it comes from. Some info here:
Mark Tinsky - Briar Blocks for Pipe Kits - American Smoking Pipe Co.