Remington 1100 LW 20 gauge

[sawmill66]

I have a 1100 LW that has a LT 20 gauge style barrel, and the receiver has the larger style LT 20 ejection port. The barrel is marked with Remington name and all markings including LW 20 on barrel. The serial number is M590643K, and the receiver is marked Remington Model-1100LW. The barrel date code is LO. This gun looks to me it was made this way at Remington. I can not see where there was any ejector made on the receiver. I think the date codes on gun and barrel date to 1977. How is it possible to have a LW barrel with all correct Remington markings and have a long tang like a LT 20? Can anyone explain how this is?

[Mainspring]

I don't know the answer. It might be a transition piece before the final design was settled upon, or a cleanup of parts on hand.