Kawasaki Triples Club

Hi guys. received some crusty carbs from the states for my h1e . they are very rough indeed. they are 500 carbs but don't know which year. they have the ISO stamp and the wing logo up top but theres no kae 1 or kae 3/4/5/6/. seller sold as just 500 carbs. also only the middle one has a plate in it ? tm thinking they may be super early ones or should all three have plates inside.. wanted to fit HIE jets ect... thanks.

The one with the plate in is KH 500; this will have a 25 pilot jet and not a 30.
Are you looking in the right place for the stamps, if they're very crusty you might need to wire brush them to see the marks

Gary T