I sorry if this has been posted before. I'm new here.
I have found a number of dead links. I was disappointed to miss the information.
Then i remembered there are internet archives such as the way back machine. I googled way back machine to get the address.
So for example the "trailer frame building tutorial" leads to a defunct site.
I copied the url of the link.
Then when to https://web.archive.org/web and pasted the url into their search window, lo and behold there was the tutorial.
Hope this is useful.