Jack First Gun Parts is making some replacement parts for the Old Army.Actually I find using a press faster than loading on the pistol.
Beside the advantage you pointed out in using a press there is another one. Ruger has no spare parts for Ruger Old Army's and if you damage one of the parts while loading a cylinder, you are out of luck.
A quick search of the Ruger product history [serial number] database indicates that they ended production of the Old Army in 2008.When did Ruger stop production of the Old Army? I knew it did I just dont recall when.