210-HD 130

Hello, I've had this amp since '78.  Over the years I've gone thru a few sets of tubes, Billy Zoom replaced the Alinco 10's with Jensens, and I recently had to replace all the caps and zener diodes.  It weighs a ton but sounds fantastic!  The S/N is B008633.  Is there a way to pin down the actual production date or year?  Thank you!

David O'D