Sorry I missed the smiley. I did quite like the suggestion of turning the gun the other way on the bike etc. My suggestion was the wooden blocks and I have used that method successfully to straighten 3 or 4 barrels. I am not a professional but I do dabble at repairing my own antiques.
What many have missed in the discussion, is that the gun is a family gun handed down through a couple of generations, if I read the posts correctly. Economically it does not make sense to have it repaired by a smith but it certainly makes sense for the owner to try themselves and for anyone with a bit of experience, it is not outside their potential ability. You don't need a screw press to straighten the barrel but can use good stout lever for pressure and the critical thing is to have the barrel cradled with stops underneath it so that you are bending it in a controlled amount. You should also expect a fair amount of spring back and have to overbend the barrel and have it spring back to where you want it. Filling the barrel with dry sand is only of value if the barrel is extremely bent.
cheers mooncoon