Colt's split the letters in 1993-1994 - your serial number's probably closest to a 1999 production.
They're well-built, and were/are Custom Shop products.
Colt's QC problems came in the late 1970's, when the company was purchased by the UAW.
Today's Single Action Armys are 'very' nice.
That said - the price asked for a used one is about retail - and you can find brand-new-in-the-box examples for a bit less, if you look.
I highly doubt the piece ever needed an action job and I'd be a little suspect of any work having been performed, thanks to would-be 'gunsmiths'.
Vaya,
Scouts Out!