I've got a few Dealer Parts Catalogs for various AC tractors. According to these Catalogs, the Insulator, battery box cover (Part # 211435) & the Insulator, battery box (Part # 210908) are common to the B, C, CA, G, WD & WD45 tractors. (Perhaps others - these are the ones I had that matched.)
I have a G that I'm working on. I've never even seen a complete original metal Battery Box - let alone the insulators. The B IB C Parts catalog notes that these Insulators were made of wood. Sounds like the insulators could be reproduced with some common woodshop tools - if the dimensions of these insulators were known.
Question: Does anyone have knowledge of the dimensions of the top & bottom battery insulators? Even better, does anyone have the actual insulators? I'd be interested in the type of wood as well - plywood or whatever.