Walther LG90 seals

[jmaurer]

All - I've got a Walther LG90 that's not holding air well. I can hear it leak a bit when I pump it. Subsequent pumps/shots seem to improve its ability to hold air, and after half dozen shots it is up to semi-normal velocities. I assume it's the piston seal and that continued pumping/shots expand it? I do not appear to be losing air at the breach.

I've not found anyone that reseals these old Walthers. Tried Champion's Choice, Earl's, David, Randy, etc. So...

1) Anyone have another gunsmith recommendation? Or,
2) How difficult is the seal replacement (assuming I can find the seals)

thanks!
Jeff