There are a few problems with the dimensions that I have from the HDM. The crate in the HDM has plexiglass in front, and the curator can't get exact dimensions for some of the interior parts, and I don't want to be a huge pest about this, but I think I have everything i need to draft some real close dimensions. He was unable to get anything close for the inside wood blocks, but the engine case itself has a few known dimensions such as the distance between the left and right side mounting holes, the difference in the height between the two engine mount shelves where the mounting holes are, and things like that. I have the width and height of my NOS carby box, so I can do a bid of reverse calculations to make this work.
Also the overall dimensions given (heigth 21.5", width 27.0", depth 15 1/2") included small portions of the front and rear panels which were sort of ripped off leaving pieces on the lower edge. Given the nominal thickness of those pieces at 3/4", I make the depth of the case without a front or back cover to be 14" I plan on building just the circumferential shell without a front or back panel, and then adding two pieces of plexi-glass as view windows. Those will make the case rigid.
The thickness of the top and bottom panels are each 3/4", so I subtract that from the total height to get the height of the side panels at 20 3/4".
I'll transfer this all to a spreadsheet, then make a list of materials. Give me a few weeks to sort it all out.
WLA SN 42WLA56511, USA-692406
WC-12 SN 8682327, USA W-231808
WC-12 SN 8678633, USA W-223982