Ok, understand there must have been a reason behind it but what desn't make sense is the undersealing was uniform and professional, I mean all the seams were sealed, or the edges were beaded, if someone rushed it and just bolted it together I can't see why they would have gone to the trouble of the undersealing. I've yet to do the rear section, but from quick observation it looks normal. I still reckon it rusted out, they found some panels, and didn't have access to a welder (not uncommon here in Ireland in the 80's I've heard, especially a MIG) and just bolted it together. As I say I will unbolt it all and have a look, maybe then I'll understand why? Oh and the front firewall looks original and is welded (spotted) so it's only the front floor sections?