Hi Lee / Bill
We will have to take a good look at the 455 Target at the annual meeting. I can not see any gap under the front sight boss.
it was made in the tool room in 1916 at the request of Joe Wesson for his friend Hereshoff. So your guess is as good as mine. When you are the President of the company you can get anything made you want.
In my display at the annual meeting this year there will be 4 more original 45 colt revolvers that letter as 45 colts.
Jim Fisher