Are there any other model that have similar valve stem seals? Need for NC29 and NC23 Aero.

http://www.davidsilverspares.co.uk/part ... 208KY2003/

it is 12208-KY2-003 for the NC29..

12208 is the general Honda code for the valve seasls.

NC30/35 has different ones for intake and exhaust. I can probably post you one of each from a spare head if you think it would help?