Will a 336 hammer work in a 39D. I have a spare 336 hammer. Looked at them and they look the same. Tried to get the hammer out of the 39. Looks like the piece the spring fits on has to come off first. Gun smith worked on the trigger but didn't do a good job. Thought if the hammers will switch I could try the spare one. Nothing to loose except a little time. If I ruin the spare that's OK.