Found this beautiful drippy 2-tone Locke recently. After struggling a bit to identify the U-#, and then conversing with Elton, it has been determined this is a previously unreported U-706 with the Locke incuse embossing. It's probably safe to assume this isn't rare and there are others out there that may have been lumped into the similar U-705 design, but it's worth re-examining your triple petticoat Locke's.