Wayne,

I recommend you isolate the problem as either electrical or mechanical (if you haven't already)

If electrical, the unit won't do anything. If mechanical, the recoil motor will try to work (you can check this by touching the recoil motor during a recoil event. If it is trying to work, you'll feel it. If that's the case, pop the motor out of its cradle, and then hand cycle the recoil unit back and forth. You can easily bend the metal shuttle with a pair of long nose pliers. Once it works freely, reassemble.

If you need to take out the recoil unit, the recoil stay will need to come loose from the back side of the mantlet. You'll also need to disconnect the black ABS part that connects the barrel to the recoil unit (on the F sprue). Once you do all that, it should come out. Tight, but not impossible.

As to the F1 and F2 parts, I usually can repair them 80% of the time by melting them together using Tenax (which is MEK based). Just give it plenty of time to harden up after you do the repair.