Joined: Jan 2010
Posts: 9,831
Likes: 1,809
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
Easy fix since this is a steel bike. I have fixed many like this.
Keep the rear wheel installed, and using a 2X2 piece of wood as a drift punch, tap the tube back (right at the bend) using a 3-pound hammer.
It will help to have someone hold the bike upright. I would take my time and use a dozen or so calibrated blows to get the tube straightened but not "over-straightened". It should come out almost perfect in my experience. Do not hit the tube with anything harder than wood, or you'll flatten/collapse it.