I customized my PS97S with the help of TT user Geoff - so he'd probably have much better and more accurate info for you on customizing it. Here is what I did:
- replaced grip with a leather grip
- opened up buttcap and using screw driver I removed some of the foam in the inside of the handle (both channels) .... about 3 inches deep.
- I stuffed in about 1/2 cotton ball into each of the hollowed out handle channels. This prevents the silicone from going deeper into the handle.
- I cut up some 1/4 lead tape into about 3 inch strips and weighed them till I had about 20g (removing the backing tape). I stuck two strips back to back so sticky sides were stuck together.
- I inserted in the lead tape strips roughly equally into the hollowed out handle channels
- I used regular household clear silicone and filled the hollowed out handle channels till full
- Let set for a few hours
Hope this helps... but again I'm pretty new at this and got a lot of advice from Geoff.