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.
2012 remington express max
They didn't make them in 1942
$300.00
400 dollars
The Remington 90-t is a 12 gauge, single shot, break open, trap shotgun
The manual is downloadable from Remington's website.
About 275 in good condition