Contemplating putting the long barrel back on and getting a target hammer. (I had an 8.375" put on for IHMSA but soon went to M29 and Contender, so returned to the 3.5" that came on it.) 3.5" .357s are kewl but I'm too old to play G-man and will get more use from it as a heavy target gun.
I had changed out the hammer on my old 5" model 27 back in the 80's or early 90's as I was having problems with the original and the new target hammer assembly turned out to be a drop in for me. Of course your mileage may vary. If you do have problems you might try swapping the sear off your old hammer to the new one and see if that works before doing any fitting on the new sear and hammer.