oldgeekinnc -
You are shooting for a needle in your haystack with so few HSB in that BOW size. Have you tried a fly on the surface?
I have a similar situation - in that I have a 1 acre pond that has 16 largemouth bass in it. Their growth in one year has been exceptional, all RW at 110% up to 125%. I attribute that to the small number of LMB and the large number of forage. So you have about the same number per acre.
What is your water clarity? I can see 9', and that helps locate my LMB.
Also, did you land both HSB in the same spot, or different areas?