I was able to purchase a Jackal stock from http://www.relics.org.uk/productinfo.php?product=584
I bolted the action to the bottom of the magazine area with a longer bolt and hid this with the magazine, this needs to be a good fix as you don't want the action to have any movement .
the stock has to be shortened so you can get to the end of the gas tube to put the CO2 bulbs in, you can purchase long tubes that take 4 capsules and there for the stock could stay longer but I prefer it at this size with the 2 capsule tube. The weaver rails screw in to the stock quite well as the plastic is thick and strong, the bi-pod is a dual purpose one , bi-pod or handle. Below are some photos taken whilst fitting the action.
Below are pictures of the finished article , I am waiting for a laser to arrive and it will be fitted on the opposite side to the torch.