Did you already try moving the adjustment lever? You can increase the trigger pull in 1/4 pound increments by carefully moving the lever.....in your case, you would want to move the lever to the rear.
Instructions and photographs are available here......
Model 41 maintenance
Numrich, S&W and Brownells have the sear spring:
Sear Spring, New Factory Original | Gun Parts Corp.
41 | Top Rated Supplier of Firearm Reloading Equipment, Supplies, and Tools - Colt