A Mossberg 22 rifle such as the Plinkster depending on the condition is worth around $150-200.
50-100 or so
Check the Blue Book of Gun Values
$269 new retail price.
50-156 USD or so
50-100 usd
The 802 is a more than decent bolt action .22 rifle. It fires the .22 long rifle (.22LR) cartridge. It's a great gun.
A history of Mossberg has been written and is available on Amazon
Depends on WHICH .22 Mossberg, and it's condition. It may be as little as $25, or $250.
Made in 1976. Link at bottom of page to Mossberg .22 rifle info.
50-125
I believe the Westernfield rifle was made by Mossberg, and is the Mossberg Mdl 353. Magazines are available from Havlin Sales. You can order through their website, or send them an email. Very nice people to deal with for anything Mossberg.