[Jon Skagfeld]

Yep, that's it!

The two batteries fitted into the left and right open trays, the "T" handle secured the tops of the batteries with a right angle clamp arrangement.

Your pic looks to be in pretty good shape, usually these devices were often coated with white oxident from either boiling over, or from road-movement tipping, which caused all sorts of funny smells and residue in the operator's compartment.