I gOOgled around and found a
Thread thread that said a Master Tow requires a whole new "lower deck assembly" and that basically totals the dolly, between cost of part and labor.
Then, Master Tow shows
This Manual showing spindles as "parts" for about $70 each. I don't know whether those parts are available, and if so, if they're bolted in, welded on, etc.
Inconclusive, but that's about all I could find.
Maybe a trailer/boat trailer shop, even a major U-Haul shop could help.
EDIT: WHY BENT??? Hit Something? Overloaded Dolly?