This is true, my Grandad was a prolific scrounger of skips, at one point he used to drive skip lorries, i.e. the lorries that carry the rubbish skips from place to place, and whenever he was clearing out a factory or whatever for demolition, he would usually bring back all sorts of worthwhile stuff that would otherwise have been lost to the landfill, or scrapped and smelted down or whatever. We used to restore old cars with all sorts of skip-found parts that were no use to whoever owned them, but that were just the thing for whatever our current project was, everything from trim parts, mechanical components, even steel and aluminium for repairing the structure and bodywork. Of course, scrapyards are another goldmine for such things, although heavy handed legislation has made British scrapyards less of an Aladdin's Cave than they once were, but you can still find some strange and wonderful things in them if you're patient. Often the finds are more vehicle oriented, but that does sometimes include old military vehicles, either ones that were scrapped as they can't be sold on, or ones that were sold on and are now in the scrappy after decades of civilian ownership.