According to the parts lists, only one breather cover type was ever fitted to sandcasts (long front screw), with the first cover change occuring early during die-cast "K0" prouction (E vin 1010337) when the cam cover itself was also changed. This second type breather cover was also a long front screw cover but with a subtle change in cover height.
Whether or not there were any changes in breather cover casting detail during sand cast production, I do not recall.
The cover shown with a short front screw fixing and internal baffling is from a much later K series bike (K6, or possibly even later).
Cheers - Chris R.
