Glenn your alloy is in the area of 6.5 BHN--- 8 units of lead [5 bhn ea] and 2 units of ww alloy [24 figuring an aged hardness of 12 bhn] as cast [64 divided by the 10 units]. Thing is-- your compressing that alloy 6 thou which I'd think has to help some. Tin/lead alloys also age SOFTEN to some degree-- ww alloys age HARDEN if their as cast.
What works works.. just run with it!