When eliminating the SRIS on the GT550 and remove the ugly 3 hole grommet, you are left with a large hole in the oil line area. I didn't like the appearance with the grommet omitted. Scratch my head and went to my junk pile. I found a handlebar end plug. It fit perfectly and even snapped into place. Not a landmark, but I was happy

I was born with nothing and still have most of it left.
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1978 GS1000C
1976 GT550 ongoing money pit.