Just acquired a like new 20ga DHE with an extra set of 16ga barrels (courtesy of Galazan).  When Mark Beasland received the gun and we were looking it over, he remarked on the 16ga forcing cones.  You can see a line at the end of the chamber, then a faint shadow (fairly long) rather than the typical much darker forcing cone area.  But we didn't look at the 20ga barrels, which are factory Parker Reproduction, to compare.  I did when I got the gun home--and discovered that they looked exactly like what I saw in the 16ga barrels.
So I then compared to my 12ga Repro--and discovered that it didn't have the unusual cones (or almost not-cones).  Standard darker ring where the chamber ends.  I've owned several other Repros, and as best I can recall, there was nothing unusual about the forcing cones.  But since I no longer have them to inspect, it's possible I might have missed one that looked like my new 2 barrel set.
Anyone else have a Repro with different looking cones like I described above???