I guess that was a great engineering feat? Exactly how much differently patterning was it than a factory Parker? The barrels were somehow differently configured at the front or back ends?

If you do the trig, you'll find that in order to move the pattern any significant amount, you either have to change the barrel configuration drastically, such that the barrels look a lot different or egg out the chokes. If the original barrels patterned well on a production gun, new tubes stuck in the breach end and soldered all back together is almost always going to result in the same outcome, if the work is any good.