I recommend buying the Kuhnhausen book before doing anything.

"Usually" the correction for early bolt drop is to bend the "tail" of the bolt in toward the rebound lever.
This will delay bot drop and drop it into the leade before the actual cylinder locking notch.
Note that you remove the bolt each time you bend it. Attempting to bend the bolt while it's in the gun will often snap off the head of the bolt screw.
Like most parts Colt, the screw usually has to be fitted.

Having to totally disassemble the action each time you make a small bend in the bolt then reassemble to see if it's right is one reason Colt's are so aggravating to work on.