I think there is a Target style hammer for the J-frame. Call customer service and ask for the parts department.
Recently made triggers should fit your M63, despite it's age (whatever it is). Hammers from the forged era are identical to current MIM hammers, due to the M63's rimfire design has always had a frame mounted firing pin.
Just be advised, if you go the used route, a hammer for other Smith frame sizes won't fit.
The Model 63 came with a .375" wide "semi-target" hammer spur. I'm not aware of a .500" wide "full target" hammer spur for the J-frame.
Here are pictures (left to right) of an L-frame Model 686 that you wanted to duplicate the feel . . . a J-frame Model 60-4 . . . and a J-frame Model 63. All three have factory standard .375" wide hammer spurs.
Let us know what S&W Customer Service comes up with.