Though it came in a rather ratty looking box and none of the fasteners for the cover could be found, I scavenged enough screws to fasten the cover on the inverter and put it back into the engine compartment where it belongs. It ran a bit inconsistently at first, something I racked up to some bubbles in the coolant that triggered amp limiting due to temperature but once that was worked out it ran like I remember it-almost. I think I have to get a few cycles on the batteries to wake them up again. They were left inactive for about 6 months fully charged, but nevertheless it’s still a shock to the system that will take a few cycles to absorb.
For some reason, power wasn’t getting to the front of the car so no headlights, wipers or vacuum brake assist. In the process of disconnecting everything to diagnose the inverter problem there must be something yet to be hooked up.
Once everything’s buttoned up I’ll post some video.