My first question is how do I go about cleaning it or do I need to?
Also I read that its drilled and tapped for receiver sights, anyone recommend using one and if so what kind? Also is there anyway to mount any other type scope or sight without drilling or tapping that might mess with its condition?
I have bought from these guys before for other stuff and notice they have some interesting accessories but wasn't sure if I could make use of any of it without messing up the condition of the gun.
Finally is there anyplace I can get the manual? Preferably a digital scan.
Anything else I should know about this rifle? The best ammo, etc... Any additional advice?
It's always a good idea to clean a rifle that hasn't been cleaned or lubed in some time. It's probably dirty, and the lube has probably dried out.
Here's a link to a online manual. You can also contact Marlin and they'll send you a free one:
http://gunshowonthenet.com/Gun_Manuals/Gun_Manuals3/Marlin_39A,_39M.pdf
Here's an exploded view or the 39A:
http://www.stevespages.com/ipb-marlin-39a.html
If you clean the barrel, pay attention to the bit about locking the ejector down.
Also, MAKE SURE you have the hammer cocked before attempting to separate or assemble the receivers.
I recommend using a quarter to unscrew the receiver bolt. A screwdriver often chews up the wide slot.
To clean, remove the bolt and and use a toothbrush and a little solvent to scrub the bolt assembly and the inside of both receiver sections.
Lube with your favorite lubricant and reassemble.
Remember to unlock the ejector before assembly.
Depending on the age, the rifle is probably drilled and tapped for both a scope and a receiver sight.
The top of the receiver will have two holes for a scope mount, one at the very front and one at the rear. Be careful NOT to unscrew the center-front screw. It holds the upper cartridge guide in place.
There may be two screws on the rear of the receiver. These are to mount a peep rear sight.