50-100 USD
Read the roll mark on the rifle.
Best to let a gunsmith help you.
No published sn data
Despite the question mark, you have not yet asked a question. The marlin Model 80 was a bolt action hunting quality .22 rimfire caliber rifle. Value will depend on condition, but is roughly in the $125-$150 range.
Roughly $125 or so, depending on condition. Lakefield (Ontario Canada) was acquired by the Savage firearms company.
100-700 usd
Mark Savage was born in 1962.
50-150 USD or so
100-450
100-450 USD
Pull and hold the trigger, then pull the bolt back and it should release.
£275 at least