J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Vessel documentation

Here's a good old thread that explains the hull numbers and date codes.

The hull number you have is as follows:
TSP300850679

TSP - Manufacturers code for Tilliston Pearson Inc.

30 - code for J/30 (sometimes this is 00)

085 - code for hull number 085

0679 - date code of manufacture June 1979