If you can PROOVE that it's never been fired...about $600-800
about $500 as described
The winchester 25-35 Cartridge CAN be safely fired in a 25-36 Marlin caliber firearm. They are similar cartridges, the Marlin is a bit longer. For that reason the Marlin ammo cannot be fired in the Winchester.
Don't know about the Marlin M specifically but a general rule is that 22 lr will and can be safely fired out of 22 magnum caliber weapons. Much like .38special will fire out of .357 magnum.
Has it ever been fired?
50-350 USD or so
That is the Marlin proofmark, showing the gun to have been test fired with a high pressure "proof" load. It stands for the initials of the founder of the company- John marlin.
It only comes as a striker fired pistol - the design cannot accommodate a SA-type action (and the existing action isn't DA, to that end, as the striker fired mechanic is much different from a hammer fired mechanism).
350-400 dollars.
Depends where you live. Also it matters if its the 1894 cowboy or the 1894 cowboy limited. If it actually is a cowboy limited it matters if its the 20'' or the 24'' barrel. If in fact its the 24'' cowboy limited and in good condition people will pay 800-1000. They are very hard to come by and marlin stopped making them when they were bought by Remington.
The Marlin Model 1881 was Marlin's first lever action rifle. It fired much more powerful loadings that the Winchesters and it beat Winchester's Model 1886 to the market by 5 years. Condition is everything in antique guns. If it has been refinished, the collector value is very low. If it is in original condition with the expected level of wear but not abused it could get upwards of $2000. THe Model 81 was a .22 cal. bolt action rifle with a tube magazine. It was superceded by the 881 and the the 981. It sells for around $100-200, depending on condition. A good average price is 150-175
Mirror neurons
Try a thorough cleaning, change magazines, change ammunition. The marlin 989 was made in the 60's the bolt does not open when the last shot is fired