If either field 71F (at least one occurrence) or field 71G is present, then field 33B is mandatory
The Light Twelve Auto-5 with serial number 71G 74808 was produced in 1971.
71g = 2.5oz
71 grams = 71 000 milligrams
1971
its a 1971
71
1971
1971
Basically impossible to value with just the serial number.
Should be a 71 year model
The heaviest insect weights aroud 71g and its called the Deinacrida heteracantha found mainly in New Zealand.