I found a review, 2 guys bought a pair of Iron airsoft Lee enfields from Evike. After a lot of work on them they got one shooting at between 80 and 360fps and evike sent them another gun as parts were unavailable to get the other working. Weeks later they managed to eventually get 2 out of the 3 working at 400fps.
I think the shoot and scoot may be the safer option, I wonder if they would sell the DIY option without the donor gun parts so you could try and fit a different gun inside it?
The 2 blanket/utility straps are on their way as are the goggles and I have also bought a 2nd battery. I decided to try a 9.6V in the Sten. It has a high ROF with an 8.4V. The ROF with a 9.6V battery is actually scary for me shooting it. You can actually see how far apart the BB's are in flight and I would estimate its 2-3 inches. By the time someone shouts hit, you can have half a mag in the air. I will have to get some heavy BB's so that if I hit ricochets they don't shatter as I feel it is rather dangerous at short range atm. Fortunately I also tested the capacity of the King arms 110 round mags and its closer to 140 rounds, it did seem a bit strange that the capacity was so close to an MP5 midcap when the mags are so much longer.