It might be fun to toy around with it for some kinda hobby, but it would be unethical to return to shooters grade when you could pick up a Marlin semi-auto brand new for under $100. I'd especially be worried something happened to the rifling, but I'm sure they can be re-grooved. But as stated none of this is gonna be cost effective.
But I guess in the end its not where you go, it's how you get there.