winchester 1300 NWTH

i have had an 1300 NWTH since the mid to late 80's i bought new..it has a turkey walkin thru woods on right of receiver and on left has one stretching his wings..i bought a used one today and when comparing the 2..the 1 i got today has struting turkey's on both sides but on the left of receiver it also has ROB KECK signature engraved.it came from the factory this way.does anyone how many were made with his signature?..Thanks