I don't think it is quite that simple. Way more than one I have handled can only be referred to as "Crunchy", feeling like something was wrong internally, even if it worked.
To be fair, it is not simply a problem on Parker repros, getting a single trigger right is tough on any gun.
I think the market has determined that the double trigger Parker Repro guns are worth more. But, it didn't start out that way.
Best,
Ted
When the Repros came out, the sense seemed to be that American shooters still preferred a ST over DT. True of all the really popular sxs imported from Japan (where the Repros were made): SKB, BSS, Winchester 23. For what it's worth, Michael McIntosh thought the Repro had a better ST than did the Win 23. I tend to agree.
Similarly, back then, if you wanted open chokes on a sxs made for an American company, you got short barrels. If you wanted tighter chokes, you got longer barrels. These days, a Repro--especially in 20 or 28ga--would likely sell better if it had not only DT, but also if it were choked IC/M. Or maybe even Quail 1 & 2. The preferences of American sxs shooters have changed quite a bit since then.