Netgear MR6500 Current state

[BarrySDCA]

Newby here. I picked up a Nighthawk MR6500 with firmware NTGX65_12.01.16.01.

It seems this firmware is locked down pretty good to the point I can't edit the IMEI. Is this true? I tried looking for an older firmware to downgrade it but also was unsuccessful. I greatly appreciate any guidance to help me get this thing working.

I have plenty of tech skills, just am unfamiliar with the whole Nighthawk/IMEI change thing.

thank you

[noise_maker]

My 6150s I can get into on 12.01.47 via sierrakeygen just haxe to us the 65 modem type vs 55

Not sure on the 6500s specifically though