Should be an easy call....
Muster at 43 and "out of shape" is easily a 6.0 Mens.
Bammer at her absolute best is 7.0 Women.
No way one level evens things out. You'd need either an 8.0 woman or a 5.0 mens to make the match about even.
As a 3.5 Mens, I could hold my own against some then A and OpenWomen, and I wasn't allowed to serve hard OR S/V. OR dropshot.