glue will probably not work as an insulator. It would work if it could be spread evenly and cover all places where they might be contact. However, with a liquid type glue, I don't think that is possible. I think the wheel would rub some of the glue away when installed, and make contact with the axle.
You might be able to put bushings on the NWSL axles to keep them from floating. A brass tube would probably work as a bushing. You might find Oilite bushings in a small enough size at a special hardware store or on line.
You might be able to use a plastic tube to insulate the wheel hub. Plastruct makes many tubing sizes.