Battery Carrier

Amelia is completely devoid of any battery carrying facilities. She should have the big Lucas GU11E battery that appeared in 1951.

Thanks to Brenton Roy & Guy Rayner of the AOMCC for these images of what I need to make, find, swap or a combination of the three:

What I need is the dimensions of this part. Anyone measure one for me?

Underside, showing the screws that clamp it to the primary cases.

Here is the strap, best English chrome plate, available from Acme Stainless in a rather more appropriate material.

And here is the large battery carrier, in position on Guy's 4G. As he says, his bike should have the small battery. Alas I don't have one to swap...

As a postscript to this request, the ever helpful Brenton sent me this:

We'll be making one of those later.