Take it to a gunsmith.
You find a gunsmith.
Tough question, the Remington model 550 is a .22 rifle not a 12 gauge shotgun.
$300.00
Visit the Remington web site.
sawed-off double barreled 12 gauge Remington shotgun.
$300.00
They didn't make them in 1942
2012 remington express max
400 dollars
The Remington 90-t is a 12 gauge, single shot, break open, trap shotgun
100-1000 depending on specifics
Blue Book of Gun Values