Nice that you liked it
They cut away all the rusty parts and replacing them with new ones..
The lead soldering is not a way to prevent rust, the only way to prevent old rust from start rusting again, is to cut it away
But the lead soldering is instead of two component body sparcle and such..
If you have worked with it (body sparcle), you know it's a mess and hard to get a good nice kleen surface without dents, if you are to fill large holes..
I have never seen this lead soldering technique before, but it looks quite good, works only on metal though
In this case they end up with almost changing all the sub frame.. And most of the body
It's all rust.. poor guys.. Can't say anything about the motivation and will to get it dun though! Any other reasonable person would have gotten rid of the project right after stripping it