David,
If you find some, I'll be thrilled. I haven't found the time to get over to my friends shop to bore the thru-bolt hole shown in this pic. Once that's done, it's fairly straightforward work. So many things going on that I just can't find time. Soon, soon, ...really.
BTW, for those of you contemplating doing this yourself, I'd highly recommend laying it all out, in full size tracings, on craft paper. Include the barrels and especially the rib line and desired comb line, butt length, lower line of the stock, etc.
When you have it all layed out, you can determine the best cut line for the grip,
1)cut and finish the grip mortise, (this cut locates the joint, so try to place it in the checkering of the grip as much as practical while maintaining all the dimensions for strength)
2)put the grip on the gun back on the craft paper layout, transfer the line of the grip joint to the craft paper
3)lay the new blank on craft paper layout, ensuring the comb and other periphery lines are within the blank's size (be generous and allow at least a 1/2")
4)transfer the joint line as accurately as possible to the new blank (an error in angle will shift the butt up or down, so take care that the angle is correct)
5)cut the new blank joint angle and finish the tenon.
6)dry fit the butt blank to the grip and assemble on the gun and place on the craft layout.
7)doublecheck the comb, butt, and all other periphery lines to the butt blank.
8)I had enough wood to leave a chunk near the comb that allowed for easier clamping (see pics), but you could also glue a piece on to help anchor the clamp or put a screw in from under the triggerguard tang slot as Mr T recommends.
9)Glue the butt to the grip
(for drawbolt guns, you'll need to drill it at this time)
10) place the fully assembled gun on the craft layout and check again, layout your final lines
11) cut the comb line and other periphery lines leaving a bit for working it down. (at least 1/8" or a little more).
12) work the butt shape and dimensions to suit you.
