What is the proper way to assign a hull identification number to an old boat?
The boat is a Dark Harbor 17 1/2 built in 1919 (originally called the Manchester 17-1/2 designed in 1908). It has sail number 25, so I assume this is the 25th Dark Harbor built. The designer is B. B. Crowninshield. When purchased by me, there were no identifying numbers.
Is there a formula used to develop the number?