Marcus,
Are you working from a detailed set of plans/blueprints?
Do you plan on using both blind and bucked rivets in your chassis?
Will you be using any structural epoxy along with the rivets, or will the chassis be mechanically fastened together only?
Do you plan on using any conversion coatings?
I have aircraft structural sheet metal repair/modification experience. I trained under an elderly aircraft mechanic who built Consolidated B-24 Liberators at the Willow Run plant in WWII. He could build anything out of his head with no plans, just give him a sheet of 2024 and watch him go!
Also if you need to locate a difficult to find item, please don't hesitate to ask. I'd be happy to oblige.
I look foward to watching your car come alive.
Best regards,
Scott