The number stamped on the handle is probably the model #; Model #76 was the "Throwing Dirk". Not sure what the "57" stamped on the blade means. The star or stars around the Tru-Bal stamp are just part of the logo, I don't kow if they had any particular meaning or if they changed over time.
As with so many other things, value depends on model, condition, age, etc. My brother sort of collects these; from what he has mentioned, a common model in good condition might go in the $50-75 range. Best bet for getting a better line on price would be to watch eBay.