Val,
I've never heard of that but I do know that there was a barrel maker in the 1940's named Gregorie from New Haven CT that made high quality cut rifled left hand twist barrels, very similar to Pope.  A local gunsmith in New Braunfels by the name of George Klaus, built hundreds of guns over the years for the local Vereins.  His work is distinctive if you have seen a number of them.  Most of the rifles I know of were built in the 1940's thru the 1960's built with Gregorie or Sukalle heavy 22lr barrels.  These rifles are still prized possessions in the club today.  I've seen his work on Ballard, high and low wall's, 44, 44 1/2 and Winchester 52's up to the B model.
The point being that I wouldn't be surprised if these Gregorie barrels could have been used as liners to restore a damaged Pope barrel.   
I suspect that Pope would have marked his barrel in some way if he took a 2nd bite of the apple.
I own a false muzzle low wall, pistol grip single set trigger 28-30 that when it was 1st offered to me was claimed to be a "unmarked Pope".  I don't buy that story, but it's still a cool gun.
That's a long way around Harvey's barn to say if Pope didn't mark it, I wouldn't have much conviction in the story.

Supposedly this fella said he'd seen numerous various single shot rifles with barrels marked by HM Pope and had Pope liners in them. In 50 years of collecting single shot rifles I've never seen this myself, and suspecting he's making this up to cover a statement he made about Pope relining "lots of barrels". 
According to Ray Smith Pope had a sign in his shop stating he didn't do repairs unless it was an emergency. I'm not sure how he could ever make liners that met his strict standards as once a barrel was rifled it would change dimensions if turned down to become a liner.

Smoke wrote yesterday at 6:42pm:


All of my Pope barrels have Pope's numbers stamped under the forearm, and his HM Pope stamp on top flat. Exception is that Rolling Block target pistol I bought from Eric, and it has Pope's HM Pope stamp under the forearm too. 
Numbers are his serial numbered barrels, plus the twist rate data he stamped on them. If he ever made a liner I'd think he would have also installed it, and not sure how he'd mark them?

did pope offset the bore for CF to 22 conversions like Hubleck? I believe I know where a pope CF  offset  to 22 short done by Hubleck Is I think is.