[Sans Peur]

I think this gun may be a 125 (Not L 25). As you will know the 'original' Belgium made Browning superposed is the model B 25 and subsequently the Japanese made models have 25 in the title, starting with the 125 and now up to 625 I believe.
The Japanese (Miroku) made Brownings are as long lasting and reliable as the originals but I have no idea of values in the USA or of manufacturing dates. The chokes in this gun would be an 'aftermarket' addition.

 

[Sans Peur]

Apologies for doubting your read of the marks
I had never heard of an L25 but looking on Google.com a couple of them come up also referenced as Citori so perhaps its the original designation for the Citori Japanese made model.
There are many people on here more knowledgeable than me on these things and I have no doubt one of them will give you the full story.