The 80 Amp circuit breaker on our MEP-1050 was defective and would not stay in the “On” position so it needed to be replaced.
We found the part with a reasonable price at Powerwerx – https://powerwerx.com/ – for $54.99 plus around $10.00 for 2 business day shipping. The Powerwerx SKU number is CB187F-80 incase you need one.
The circuit breaker is mounted with three hex head screws but the problem is that there are also nuts on these screws and the nuts are behind the wall that the circuit breaker is mounted on. Here is the new circuit breaker mounted:
Here is a photo of the 24 10 mm bolts that need to be removed for the front cover to access the three nuts for the mounting screws:

While we had the front cover off we cleaned inside the cabinet a bit and also found some bags of miscellaneous screws, nuts, bolts and clamps.
This was an easy repair replacement despite the 24 10 mm bolts that needed to be removed so on to the next issue which is the fault code 3665 and 3664. Fault code 3665 seems to have something to do with the voltage selection board not matching the control panel’s output voltage setting.
One of the Steel Soldiers members pointed out that we have a “banjo” bolt missing on the turbo oil line. and we also noticed that the air cleaner housing is missing the bottom cap and the filter element so we need to find sources for these parts and get them before we try starting the generator. Stay tuned.