Gunch;

The rusted areas you show in your pix is totally typical...I've seen, er... had...it a lot worse before my last resto session...but that repair doesn't look too bad either...welded would certainly be better structurally, and I would certainly recommend welding replacement crossmembers in (allthough airplanes are certainly riveted, and structural strength is obviously quite important to them, but that's why they use a zillion of them!)

Rest assured, your car IS a time-bomb as you say...but thanks to Swedish steel, and the original tank construction, and the original galvanizing, the clock on that timebomb is ticking a whole bunch slower than just about any other car! ...so you better fix it quick, before it blows...(read within the next five years)!

My advice: If you like the car, fix it and enjoy it! If you saw that amount of rust on a young car, you could estimate the rate of cancer and act appropriately, but you are talking about a half century old car here...so wire brush prime and paint or conversion treat and paint all rust in sight...replace those cancerous box sections...and replace those missing mudflaps after repairing!...they contribute to the rusted cross pieces!

Maybe I should put a quantity order together and have those 304 SS pieces made finally...see: http://www.sw-em.com/DeLorean.htm who's interested?

....those damn Volvos just dont last!
Cheers