Sorry all, I couldn't add a pic to a PM for a buddy, so I used this forum.
I think that your gauge set may have been assembled with the 27 & 28 TPI gauges in the metric set by mistake.
The 28 is VERY close to 0.9mm ( except angles of course)
The 27 doesn't seem to fit between the 0.75 and 0.8mm
You may have to copy the pic and brighten it to see it clearly.
Cheers
I think that your gauge set may have been assembled with the 27 & 28 TPI gauges in the metric set by mistake.
The 28 is VERY close to 0.9mm ( except angles of course)
The 27 doesn't seem to fit between the 0.75 and 0.8mm
You may have to copy the pic and brighten it to see it clearly.
Cheers