Take the starter to a rebuild shop and see if it can be fixed. A number of years ago, I found that there was nobody left in Maryland who rewound them, if that's what's needed (was a source in Georgia, as I recall). That armature may be part of the problem. I ran '57s.
You may need only cleaning and brushes, maybe a new Bendix. Again, ARCO (in Florida) is a good source and good customer service if you don't have a local shop.