So there are two different positions for blue diamonds on clips.
One below the curve at the top of the clip and
one that straddles the curve.
Is this a random occurance or does it signify something like
year of manufacture?

I think it is between the earlier ones and the later ones and the Canadian production has the clip very high up I recall.

Jim

Jim actually has this right....

The position of the blue diamond was kind of hit and miss on the US made pens, some being a bit higher than others.... BUT the Canadian production pens all had very high blue diamonds in relation to US production.