Other than drifting those onerous splined pins over and over again, there is some consideration to doing this...
The tolerances and variances are as great in the center-to-center locations of the pin holes from gun-to-gun as are the variances between the hinge pin to standing breechface from gun to gun. That is why they insist on fitting the spare barrels at the factory.
We are only talking a possible few thousandths here. However, if you remove material from Hammer/sear by honing to a 2.5 - 3.5 lb. pull in one gun, drop out the parts and install them into a second Handi/Pardner, problems can arise. If the center-to-center distance between hammer/trigger (sear) pin holes on the second frame is a few thousanths greater, this COULD result in a dangerous lack of contact between the hammer and sear.
If you do this, follow these tests for positive trigger engagement after assembling in the new frame. Cock hammer and try (not too hard, just good thumb pressure) to push the hammer forward. If it does not fall, pad the frame side and whack it fairly good from the side with a rubber mallet. If it still holds cock, slam the recoil pad or buttplate fairly hard on a padded or carpeted floor.
If all that doesn't cause unwanted hammer fall, then check your pull weight and for correct transfer bar/firing pin function and safety.
And, as it is part of this trigger group, check for the barrel catch function, it could be off some.
The pin-to-pin variance could fall on the closer side, making the trigger heavier in that frame.
A lot of work. If it were me, I'd do three or four trigger jobs and be done with it.
IMHO, of course! - perklo :-)
