Buy new XLRs. Cut and resolder.
Being sortah a compulsive excessive, I would do All of them. And being so, I would also peek into the XLR holes on the amp and preamp to match gold to gold, silver to silver pins. Dissimilar metal contact thing.
Option 5. "The best connector is No connector at all". Open up the units. Cut all the ends off your cables. Solder the cable wires directly to the inside of the amp and preamp XLRs.