I use an epoxy resin. Beeswax does work, however, being a crazy renaissance faire goer, I have found that on a really hot day all your drinks taste like wax lol. There are also people that use a beeswax/brewer's pitch combo that I have heard works well.
There is a Facebook group called "Leather Tools For Sale" and a man named Wade Saddlemaker just listed a 3 piece set of stamps he called Hamley Desert Rose. Not sure if that's what you are looking for or not. The one is a 5 petal flower. Way out of my price range lol.
Here is a link to his FB page. I think he might have even come out with another set of patterns since this one if I remember correctly. https://www.facebook.com/thecrystalanvil
And this woman has some AMAZING things she makes for cosplay. I don't see why any of this couldn't be made with leather. She has books for sale and tutorials as well. http://www.kamuicosplay.com/tutorials
Tandy has a paperweight tutorial made from them. I know it's not the same, but you can get ideas from the video maybe on stitching and such. http://www.tandyleatherfactory.com/en-usd/Horseshoe-Paperweight-Video-How-.aspx
The markings look like they were done by a swivel knife to me. If you are looking for a nice natural wood grain pattern on your leather I'd use real wood. I have a few nice pieces of cedar wood that have amazing markings on it. I just case my leather and clamp it down on the cedar wood for a while to get a nice natural wood grain pattern.