I'm becoming quite intrigued by the idea of gluing pb bushes into the stub axles tubes.
I don't honestly see that there's a real risk of adhesive failure (assuming it's been used properly), but in any case it would be a relatively simple exercise to protect against glue failure I would think.
In the top bush, one could press a small ring of bush material (unmachined on the outside, over-bored on the inner) down into the stub axle tube to sit underneath the glued-in bush.
For the bottom bush, a grease retaining seal would do the same job of stopping the bush dropping out of position.