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.
Providing the process was controlled and that’s mainly down to degreasing and cleanliness there would be no issue with PB and steel. No need for secondary measures. If you were specifying it in a critical application one would normally specify a proof load to be applied after curing.
