270 is a caliber not a model...
For date check the Remington Society of America site for the date barrels codes:
http://remingtonsociety.com/rsa/questions/barrelcodes
your Remington 760 is going for between 200-350 dollars,at this time.
100-450 USD or so
425.00 to 450.00
In 1962.
100-400 USD depending on condition.
100-500 USD
50-500 usd
100-500 usd
Remington never made the Model 4 in 270 Winchester.
It's date stamped, check the manufacture date page on the Remington Society of America for details.
Remington .270, 150 grain.
No serial number provided.