Apologies if my search for a similar topic failed to turn up something on point.
Quick back story that has nothing to do with the issue: I volunteered to help an aunt try to restore a rifle she had inherited from her uncle. My brief research suggests that the rifle is a Winchester 1984 manufactured in 1905. It is a takedown model in .32 Winchester Special with a 26 inch octagonal barrel with no saddle ring. To my untrained eye, it looks like it was in used but ok shape up until a couple years ago. However, my aunt and uncle moved to Florida and left the rifle neglected in a soft case for at least 2-3 years. The finish is basically ruined, and it has a bunch of surface rust that may be deeper once I get further into the project. From what I can tell, the rust has basically ruined any monetary value the gun may have had, but something over 100 years old doesn't deserve to be in the shape it is in. Relevant and irrelevant photos attached because (1) maybe they will help and (2) threads are more fun with photos. No, I did not use the steel wool on the rifle.
My issue is that someone, likely several decades ago, torqued the crap out of the magazine tube past the point where it is designed to stop. Add rust on top of the over-tightening, and the tube is locked up tight. I've avoided really cranking on the takedown lever on the tube since there is only one screw attaching the lever to the tube. I've used quite a bit of penetrating brake-free, tried a wrench on the end of the tube where the takedown lever attaches and there is support for the interior of the magazine tube, tried slightly heating the area around where the magazine tube screws in (not much because I didn't want to risk the heat treat), torqued on the lever to the point where I started worrying about the screw attaching the takedown lever to the magazine tube, and tried the usual amount of bad language. No luck. My next thought is trying to reinforce the magazine tube with a hopefully-perfectly-sized dowel rod and using a padded wrench close to the receiver, but I'm hoping someone smarter than I will slap some sense into me and have a better idea before I damage a 100+ year old rifle.
Does anyone have any suggestions on how to break the magazine tube loose from the receiver without damaging the tube or the rest of the rifle? Any ideas would be appreciated.