Barnabus, using the "contact us" feature you can email David or Brian direct from either of those two sites and ask your questions and get the answers direct from the source.
These are not custom knives in the same sense that is discussed here so you may have a difficult time finding anyone who does know the answer to your questions on this forum. The only reason I know as much as I do is because years ago I collected David Yellowhorse and still have about sixteen, but I have no idea what they are worth other than since they are all fairly old they are probably worth more than I paid IF.............. I stumble in to someone that wants them and that coincides with me caring about selling.
Paul