Examine the hammer hooks, the scear hooks, and the trigger bar and linkage carefully - it probably just wants deburring.
It's amazing what you can do with a little know-how, and some carefully applied polishing... Something like a box-stock M1991A1 giving you a clean 3# trigger, perhaps? I could have gone lower, but that woud have been more work (and 3# is already considered 'light' for a carry piece - but it's what I'm used to...)
Note that this trigger was done with no parts replacement, and only clean-up and polish work...
5-90