I built two enforcers using magnets. Yes, epoxy for the firewall and check and double and triple check that you fuse is absolutely parallel and that the angle of the firewall at the rear is absolutely correct and that it is square with the fuse. Once you get that done the rest just falls into place.
BTW - I picked up a bunch of "welders magnets" at Harbor Freight which I find most useful. The BIG ones are great for insuring fuse sides are square and perpenducular. Plus they are heavy which is a bonus.

Good luck - it is a fun aircraft.

Dan