Good News is,
Those bushings are readily available, inexpensive & Easy to replace.
(If the beams are not warbled out)
I would recommend 2 or 3 quick "spot welds" from the bushing housing
to the axle beam. (for longevity).
https://www.autozone.com/suspension-steering-tire-and-wheel/axle-pivot-bushing
And,
Your Project is coming along Very Nicely.

Those bushings are readily available, inexpensive & Easy to replace.
(If the beams are not warbled out)
I would recommend 2 or 3 quick "spot welds" from the bushing housing
to the axle beam. (for longevity).
https://www.autozone.com/suspension-steering-tire-and-wheel/axle-pivot-bushing
And,
Your Project is coming along Very Nicely.