Munroe47, the only two officials prior to 2000 that have plate numbers were the 20 and the 22 cent coils. You can check the page on the PNC3 website,
www.PNC3.orgThe next official PNC was the 37 cent which appeared in 2002. The 39 cent and the 41 cent also have plate numbers, but of course they were issued even later! Hope this helps?
Peter