Dear Mike,

The "family jewels" joke, it seems to me, is more of a verbal gag than a visual one, and so the shape of the literal jewels is not essential to the gag.

The expression "family jewels" is yours - - Kinbote speaks often, but only, of "crown jewels" - - surely not a distinction that requires any expertise.

The family jewels are, so to speak, where the family jewels would be expected to be.

Buried in a hole in the ground?

Perhaps a jewelry expert could tell us: is it laughable that some 18th-century Zemblan emperor, maybe even Uran the Last, might have added a piece of paste jewelry to the crown-jewel collection?

The cold hard fact is that, even in the novel Pale Fire, there is no actual Zembla, hence no actual crown jewels.  So if the country & its jewels are paste, why not just let the Russians have them and keep the last laugh for yourself?

Let's agree to disagree on this one,

Carolyn