I *believe* that Jhoneil got assistance from Chris, when he was building his bow.
If you have questions, you can try Chris out. He is usually pretty helpful.
And he does have a tutorial on thumb ring shooting, if you are going to go that route.
Thomas Duvernay also has a shooting tutorial.
On another point, you can use Gemsbock horn, also, to use on the belly of your bow. Don't think that it is much "cheaper" than water buffalo horn. It should be possible to use "cow" horn, if you can find horns long enough to cut your backing strips off of. Some thing like a Longhorn bull used to have on his head.
Tilbilly, what horn did your Dad use? Water Buff, of gemsbock?