Many thanks for all your responses and the sense of humour
First of all, the part came off my S1 OTS but many, many months ago. I had written on the ziplock bag what the part was but regretfully, the writing has rubbed off over the time the part was stored while I have been doing the restoration. It isn't the dip-stick clip nor the gearbox breather pipe clip.
It's driving me nuts

. I have been going through all my old photos hoping to spot the part but so far, no luck
Anyway, if anybody has a sudden lightbulb moment

, please, please let me know.
Cheers. Yours aye,
George