Thought I might as well explain the pics, thank you Daryl for posting them.
The shotgun as you can see is based on a 71 Mauser and a take-down, so not your run of the mill
Remo Popular. Nice bore but with slight pitting under the wood, no cracks in the stock but I refinished & recheckered it.

The "sporter" 71-84, for all I can find, is someone replaced the rear sight on a carbine.
All the numbers match and the stock has a minor crack on the tip of the forend.
Bore is shiny as is the metal under the wood, there is no pitting but the outer metal
has some surface rust.

When I first decided to purchase this gun my idea was to create a rifle similar to to the take
down shotgun. With all the pluses I now hate to mess up a nice "collectible", a rear sight might
be available somewhere.

Any comments / or lead on a rear sight will be appreciated. --- John