I've made one (well, rough cut for now) from wood that I can slip on to my TX200.
Still trying to figure out what is the best height and make sure I'm comfortable before I make the final product.
At the moment is roughly 90mm, measured from the bottom of stock to bottom of hamster, after cutting out the rough shape.
Depending on how I sit - either resting on my knee or over my arm, the rifle feels heavy and like its going to fall over. I can stop this from happening by changing my position a bit, but doesn't feel that comfortable.
I can start cutting of little at a time, but any suggestions as to the average height your hamster is set to?