I have been a firearms collector for many years but my S&W knowledge is limited. I recently bought at auction a S&W DA 4TH Top Break in .38 S&W. The auction description was very "cleverly" written to not include any mention of the single action function of the revolver. If functions very well in DA but not in SA. Does the hand not rotate the cylinder until very late in the SA function? Could it be a DA only (it has a hammer). Two external pictures below. Any chance to fix the SA mechanism or did I just learn another lesson in not asking enough question BEFORE bidding.