Your Remington model 341-P was made from 1936-1940,with a total production of 131,604 made during this time span.The Remington society has the Date codes available for you to look up.Your barrel should have a 2,or 3 letter code that will give you the exact month and year of production.
I added the related link
Remington Model 552 Speedmaster
The Remington Model 29 Pump Action shotgun was manufactured from 1930 to 1933. Approximately 38,000 produced.
I BELEIVE YOU HAVE A MODEL 241. IS THIS RIGHT??
Made in 1911
Impossible to answer without the sn.
Check the manufactured date link on the Remington Society of America for details.