OG1,
Be careful with the vice-grip terminal connections. Even if temporary (which I assume they are), it's risky. An untimely drop of an uninsulated tool can lead to some pretty intense arching, heat and worse.
You may also want to consider venting the battery space separate form the inverter and switch-gear. I'm not sure which is which in the photos (half are lead acid?). Even a plastic drop/separation would help reduce corrosion. And, the connects you can see and service aren't necessarily the most damaging.
We drilled the vent caps and used (maple) sugaring tubing to collect and vent, via pvc pipe, to the outside. No fans; no controls; dirt cheap. It significantly reduces the maintenance needed on terminal connections over time.
Best, ~ks