Regarding making tools, I have been known to frequent garage sales and out of that I now have 3 filing cabinets (2 small 1 large) and 4 multi drawer cabinets full of various items that cost me next to nothing but could be useful someday. The handiest thing is the filing cabinets as I just dump things into them (in an orderly manner) and when something breaks I always check there first. With a welder and a grinder and a tap & die and a drillpress and all my other tools there is not much I can't fabricate on the fly. The things I look for include the following: anything brass, copper stainless or mild steel. Cast iron is not kept. Round and square tubing cut to lengths, ready rod, any size, dowling - wood and metal, screws, bolts and nuts of many types, sheets of metal such as copper and brass and tin, sheets of rubber and cork in varying thicknesses,old bearings, angle iron and wheels and jacks and oh heck - I keep most anything that could be useful someday. But most exciting is a big box of old tools that are made for cutting up and bending etc. I only started collecting the custom tools after I got a few from a coworker's husband's estate - he built race cars from scratch and was a rolls royce mechanic by trade - he had the most interesting wrenches (missed that garage sale by 1 week - I got the dregs).
At many garage sales there are free boxes and many times there are tools in them that have seen better days. Last month I picked up a double ended adjustable wrench made in germany probably in the 60s. The lady said that it probably came out of her late husband's car - early 60s 190sl. And to add insult to injury the family took a whole truck load of metal pieces and tools and car parts to the recyclers last year to clear out the garage so the caregiver could park out of the rain - I bet they were all old mercedes parts as her husband was a german car mechanic....
Once I cleaned up the wrench I put it in my Pagoda tool kit - I call it my secret weapon. Its not in very good shape but its cool looking.