I couldn't see the pic but I'm pretty sure you will not find a stock unless you find a used one. Even then chances are great that it will require a fair amount of fitting . And usually it is quite expensive to have someone make a proper, decent looking and fitting stock for a sidelock. Although I coudn't see the pic, I'm sure the original stock could be repaired by a competent stock man. They can do some fascinating things. I had a badly cracked stock repaired for a vintage english gun that had been all nailed together. Many vintage gun enthusiasts would rather have a repaired original stock as opposed to a replacement stock. And it's cheaper than making one.