Thanks for the detailed responses, guys.
The KLR hole isn't too bad at all... it actually looks like it's stripped for about the first couple millimeters then it is fine from there on in.
Part of the problem is that I don't know the measurement of the banjo bolt-in-question. I know it's a 7mm head - not that that means anything. The threads themselves are very close together and do not stick out as far as a normal screw or bolt. Here is a picture of the banjo bolt side-by-side with the philips-head bolt from the KLR mounting hardware:
