A Marlin Model 60 is a very popular rifle. To find an inner magazine tube for this firearm, you can turn to your local gun dealer. There are also a variety of online resources available that will offer this piece for sale.
Try e-gunparts.com
www.midwayusa.com
Never heard of a Winchester model 80. There is a Marlin model 80.
Try e-gunparts.com, gun shops, gun shows, internet
Try contacting Marlin parts. Consumer Parts Orders: Consumer Service Dept: (800)544-8892
I would start my search at numrich gun parts corp.
Gun shops, e-gunparts.com, gun shows, want ads, etc..
The Ranger model 36 is the same as the Marlin model 80. Go to gunbroker.com and type in "Marlin 80 magazine" in the search window. The cheapest one I could find was going for $18 plus postage.
Try Numrich Arms, they have a website and a lot of used and new parts.
Contact Marlin.
Good luck. Every site on the Internet seems to be out of the 10 1/2 inch magazine tube for the Glenfield/Marlin 75. Keep in mind, the Marlin 99M1 uses the same tube, but that is just as hard to find. I have been reading up on converting it over to a Marlin 60CC Magazine Tube inner and outter, but not even sure that will work.
You can purchase a replacement 7 round magazine from Numrich Arms at www.e-gunparts.com. The Part Number is 403080B Cost is $19.95. It is the same magazine used in the Marlin 80 Bolt Action rifle. Happy shooting!