My approach to "Who made what?" has been to educate myself to some degree on frame styles and variations made by the major manufacturers. Once you can recognize the differences between the "major" manufacturers, you then become your own base of knowledge. When you don't already know, ask someone who does and add that new information to your own book of knowledge.
For example a Schwinn built frame looks like a Schwinn built frame regardless of if the head badge says Excelsior or Joe's Hardware.
Does this Hawthorne have a curved lower main tube and the rear chain stays kick up in the back? Well it must be Cleveland Welding...
Does this Western Flyer have pointy drop outs and a tapering top bar? If so, its made by Murray....
Does this Hiawatha have a split wishbone at the seat post? Oh yeah, that's a Shelby characteristic....
Does this goofy little disproportional kids bike have plastic bearings in a BB poorly welded to the seat tube? Must be from Stelber...
Does this bike with no head badge or original paint have double curved top bars and the top one drops off sharply behind the seat post? It's a prewar Snyder.....
Once you learn a relatively small number of details that were proprietary to the well known makers of bicycles, you can then identify about 90% of all bikes that you ever run across.
Then you can write a book for the rest of the people who want to take the easy way out........