The differences between old and new model

run deeper than simply having one cylinder and the safety transfer bar. The new model has a slightly larger bore diameter to accomodate the 22 mag bullets. It also can carry six rounds safely with the transfer bar. The rear sight is also adjustable on some of the new models (a nice feature)

The old model has the "correct" bore diameter for a long rifle and no transfer bar as you noted. Ruger will change it out for you but there is no guarantee that you will get your old parts back. Sometimes you will and sometimes you won't, it just depends on who does the work and the shipping. This is important if you want to use the gun as a collectors item. If you want to use it as a shooter, go ahead with the conversion.

You can go to ruger.com and tell how old the gun is by the serial number. I have a new model convertible and my dad has an old model striclty long rifle. To tell you the truth, I can't really tell a difference between them on accuracy. His has fixed sights and mine has the adjustable. Mine is stainless and his is nickel plated.

Hope this helps.

Sasq.