There’s no markings because boards of that period never had them. At best, you might find the length written on or near the stringer. It was common to see the length as part of the serial number on many boards. Like: " 2316-68" with 6’8" being the length. You never, never saw dimensions written out and rarely a shapers name. Shapers often used initials or a symbol, but most boards had few markings besides a serial number and many didn’t have any number at all.
So, check back later and you might well hear from some of the guys who knew that crew.