GOOD NEWS EVERYONE [/Farnsworth] I now have four shields to spare for my twenty Temple Guards! I visited two additional Wal*Marts. The second was a bust. But the third yielded 12 more shields (once again hidden in the sewing section and cleverly disguised as buttons). @Crowsfoot I spotted that one of the cards they were attached to says on the back, "5/8 inch (16MM)", but I stand by the measurement I reported earlier of 15mm.
And now I have evidence. Earlier in the thread I said this: I went digging through some storage boxes, looking for some skinks I think I own, and look what I found instead: I was right. I had bought some buttons many moon ago. Check the price: $1.16 for three. Current issue is $1.44 for three.