part numbers on front forks

Tryin to plan ahead for winter projects on the bike already, as its a hodge podge of different bike parts i was wondering if anyone knew where part or identification number are stamped on the front forks, as i recall they were from a 1000cc kaw no idea what yr. Hopein to change seals and fork oil this winter.

Aren't any, as far as I know.

You're probably going to have to measure the forks or the seals. Z1Enterprises.com lists fork seal dimensions.
The Ohio Cafe Racers website has a fork tube conversion chart, so you could measure the upper tubes, then see what models had the same size. Also, you could narrow them down further by noting if they are the center axle type or leading axle forks. Then use the cross-ref at Kawasaki.com or Partzilla to zero in on some seals?