It seems that fishing rod makers use abalone: https://www.therodroom.com/shop/pc/SILVER-PAUA-ABALONE-p3467.htm. Also urushi suppliers in Japan generally carry it. I've purchased some from Mejiro and it is beautiful stuff. They have a presence on Etsy as well as a website, shipping from Japan is very fast.
When I want the real deal stuff and also with stick back, but many more choices I go to the source of many vendors and they get it from here. http://hawaiilure.com/catalog/shells.html