This might help:
Hull numbers used between October 31, 1972 and August 1, 1984 are as follows:
1 2 3 = Manufacture's Code
4 5 = Model Number
6 7 8 = Hull Number
9 10 11 12 = Date of Manufacture ( 9 10 Month, 11 12 Year)
Or
9 = M
10 11 = Model Year
12 = Month of Manufacture; A = August B = September
Example: TSP90014M83B
TSP = Tillotson/Pearson
90 = Model 90
014 = Hull #14
M83B = Model Year, Construction began 1982, Code B = September
Hull Numbers used after August 1, 1984 are as follows:
1 2 3 = Manufacture's Code
4 5 6 7 8 = Manufacture's Hull Number
9 10 = Date of Certification or Manufacture (9 is Letter for Month; A =
January, 10 is Last Digit of Year)
11 12 = Model Year
Example: PYZ40012L586
PYZ = Present Yachts, Inc.
40012 = Hull Serial Number
L5 = December 1985 Date of Certification or Manufacture
86 = 1986 Model Year
I hope that helps you a bit.
Rik