The gun was made in 1900, the long hexagon barrel is not unusual for that era.
Hexagon barrel what? Model? pump, rolling block, ?? Condition?
You must provide the serial number.
1910
Need the model number(Model 10,15,40,66,etc.) or, a complete description(barrel length,how many cartridges does it hold,markings on barrel)
No published sn data
Need to check the barrel date code. Remington Society of America, Manufacture date link has all the details.
The model number should be on top of the barrel just ahead of the receiver the manufacture and model should be together.
your marlin was made in 1904.
No published sn data.
Check date code on barrel, see related links
1924, that's odd, maybe someone swapped in an older barrel....
@ 1966-67