Well, you hit the jackpot, Jake. Depending on condition of the finish (bluing) and the wooden Grip Panels, value of your Low Grip Screw HSc would be between $6,000 and $10,000. By the way, it was produced in December 1940 and the run began at serial number 700 001.
If you wish to sell it, you can start here but you will need to post some good photos to open a dialogue. Anything else, let me know.