In Appendix C, on Page 3, there is a typo in the metric value of the sparkplug gap range: it should be:
0.024-0.026"/0.6mm-0.7mm instead of 0.24"-0.26"/0.3-0.4mm.

The text was corrected on Friday (7/11/25) but it will take until later this week for the new version to become available at Lulu.com. If you ordered one after 7/11/25 it will get the corrected text.
My apologies for the error to those of you who use metric sparkplug gages!

Update 7/16/25: the corrected page shows it is updated today.