[Jackarutu]

Before putting the piston spring in use hemostats to hold the trigger in place and if needed use a second pair to hold the Anti- Reverse in place. With those two locked down then put in the piston spring and align the top half of the gear box. When you get it down to where there is like a 1/4 inch or less gap between the gear case halves then loosen the hemostats and squeeze the housing together and Bob your uncle! You may have to use a scribe to align the anti-reverse shaft to the hole in the top case half as well as one of the gear shafts. It may take a little jiggering around to get the case to close but using the hemostats to stop the trigger from flying out will make it a whole lot easier.

Cheers