I didn't know the "boot grip" was hard to find these days.
I keep a little box of rubber grips, I'll have to see if there are anymore in it.
Mod 337
Here's another good grip, Pachmayr Compac (
Pachmayr® Pachmayr your primary source for quality handgun grips and recoil pads)
The older ones look a little different and I'm always on the hunt for them.
Bought these here in the classifieds.
Mod 65
These fill in well behind the trigger and are shorter than other Pachmayr grips.
GF