Help identifying crank seals Stihl 051

[Olddevonstihls]

Hi, new here.  I’ve got an old 051 which a pressure and vac test reveals needs new seals, at least on the clutch side.  I’ve ordered a set (with difficulty) but now I’ve stripped it down what I have doesn’t match what I’ve been sent and, on closer examination, the fitting on the end of the crank doesn’t match the standard parts diagram.  The diagram and the supplied seals indicates two biggish seals (30x42x7 and 25x47x7) but what I have is 25x47x7 and then, on a sleeve with a drive bar dog which engages with the sprocket, a tiny one, probably something like 15x20x5.  I can see neither this tiny seal, nor the drive sleeve on the diagram.  Existing seals with drive sleeve shown in attached photo.

 

Can anybody suggest what I might be dealing with here?

 

Many thanks.

[Olddevonstihls]

Answering my own question, it’s the oil pump drive and associated seal.