"Riding Toys" is the main source I use to ID tricycles, that along with saving ebay photos from trike listings when the head badge is shown. I also buy tricycle photographs off ebay when the tricycle details and/or head badge can be read with a magnifier. I've been able to identify most major brands of trikes made over the years, even if the badge is missing, by studying different mfrs designs and styles. I plan on doing some trike restoring on the side when I retire in less than two years.
Dave