What pellets are you using? Mine likes AA/JSB 8.4 grainers the best.

Just a thought (and I may be wrong) but 4 ft.lbs may be a bit too low as the pellet will take fractionally longer to leave the barrel and may add to inaccuracy. Something else I did while I had it apart was to polish the hammer spring strut and lube the spring lightly in a bid to shorten lock time.

Trigger fettling is down to removing the trigger and sear and polishing the contact surfaces, but be aware the small coil springs used are a complete pita to get in the right place afterwards! But worth doing as it does make a difference!