Just re-posted a pair of late 70's early 80's 13" X 8-lug LUDWIG power tom hoops on ebay. Check them out.

https://www.ebay.com/itm/70s-80s-LUDWIG-13-X-8-lug-Power-Tom-Hoops/264282499451?hash=item3d8876e97b:g:g6YAAOSwtYZcN6RB