Paul, TOTW has a Kirkland .750 mold on hand, go, boy go!

I don't know if this is the one you are talking about http://www.trackofthewolf.com/Categories/PartDetail.aspx/1204/2/AAK-619
but that one has been "Sale Pending" for a couple of weeks. In other words, it's already sold. If there is another one at Track of the Wolf, I can't find it.

Paul

Sorry. I did not check the status.
Practical machinist has a thread on making a .750 mold, has several routes outlined, including a source for 3/4" ball bearings to true the milled mold.
Amazon has 3/4" precision balls for not much, $15 for 25.
Enco has a 3/4" ball end mill cutter for $20.
Looks as though $55, including a Lee ball mold in their largest size as a donor block set would fix you up.