There are very few people with Kadett B series on here - let alone Kadett C series. You are the only one I know about! This means that many of us do not have a clue about the more essoteric aspects of Kadett C models.
See if you can load up a few pics of the affected part - then we might be able to help! Kadett C models are 'modern' to us.
Mind you - do you know of or have access to any 1.2S motor parts - particularly a new camshaft? My 1967 Kadett Rallye with its 1.1SR motor needs a new OHV camshaft.