Be careful in lightening the trigger return spring.
A little too much can cause trigger return problems.
The main spring can be adjusted upward in poundage with shims, since that model has no adjuster.
So maybe lightening the main spring and, if that proves a little too light, then shimming, if necessary, would do the job.
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”