They are resin casted clones for the combination gears for the range
and peak deviation module of the HP 8640b signal generator.
They are NOT original spares intended as a replacement of HP part/no
1430-0773 and 1430-0774.
They have been manufactured by myself as I personally own an 8640b
generator that needed a full combination gear replacement.
They are NOT a perfect clone because of the homemade/craft casting
process, but they actually work fine as can be seen @
http://www.youtube.com/watch?v=MszkI32MFPE
Hope this can help!
-Emanuele.
Link to the e-Bay auction?