Upgraded firmware, bad news

[ctsmetrony]

In trying to register my W52P with a 3CX pbx, the 3CX instructions had me upgrade firmwares for the base and handsets. For the base, I downloaded and installed 1529371429716.81.0.30.rom and then W56H-61.85.0.35.rom for the handsets. It's been a mess ever since. At one hopeful point, the base was pingable and the first handset I tried seemed to register but it went into some interminable "Initializing" message. The other handset could not find the base. I have not been able to reach the base's web page and, after another base hard reset, it is not pinging.

I would appreciate steps that might salvage this equipment.

Thanks