Seeking info on an old Sunset

I have a question for the historians.  I've got an old 8'2", Bill Shrosbree shaped, triple stringer Sunset that just needs a polish to go back in the water.  I'm guessing the board was probably made in the '71-73 time frame, but I'm hoping someone can provide a more accurate estimate.  The serial number is hard to read, so I'll let you decide for yourself what it is.  I know these were made in Encinitas, CA, but I'm hoping to nail down the time frame a little better.  Any input would be appreciated. 

Thanks,

Ray