Here are the pics of the mold as promised.
Sorry I didn't take any pics when I was making them, cameras and gloves covered in resin don't really go together. The funny lumps are used to locate the two halves of the stock correctly. When I make another one I will just use thin rolls of clay to make the locating lugs.
Basically I layed the stock on the bench put clay around it to half way up the sides. Then I put the real estate sign around the stock ( having already cut out the hole for the stock) then fill in gaps with clay. I then filled the barrel channel, action area and floorplate with clay but had them sticking out from the stock to form a lip. Then 4 layers of wax and then hairspray.
Then mix up the resin and hardener and add silica to thicken.Cover the whole stock in this and wait for it to go tacky, it sticks to your glove but pulls away.
You need to put heaps in any corner as the cloth won't stay in tight bends.
Once the resin has gone tacky then coat the whole thing in eigt layers of 6oz cloth. Ideally use 50:50 ratio of cloth to resin by weight. Work the cloth well with a roller or brush ( cut the length of the bristles in half to make the brush stiffer) to get out any air bubbles.
Then walk away for a week.
Now flip it all over remove all the clay and the real eatate sign but leave the stock in the mold. Add more clay in the barrel channel etc and repeat the whole process.
Then cross your fingers and separate the two halvesof the mold, don't use anything metal to do this as it will scratch the mold. I used a plastic fish slice and a wooden spatula.
Once the molds have been separated wash them and then sand with 400, 600 and then 800 grit paper. Wash in between each paper.
Now you are good to go. Making the two halves of the stock is the same as making the mold. I didn't use enough of the resin in the corners around the edges of the barrel channel and when iremoed it from the mold the cloth pulled away leaving the resin sitting in the mold, cosmetic only, not a structural problem.
There are heaps of videos and websites out there on fibreglass molding, but almost nothing on making gunstock. But fibreglass is fibreglass.
It is definetly not hard to do. The last bit of fibreglassing I did was 30 years ago when an Uncle showed my brother and I how to reinforce our canoe hull.
Hope all this helps.