One hears of this Queen of Siam thimble, but one never sees the darned thing. Hmm. . .
The other thimbles referenced I have not heard of before. Which means nothing.
That thimbles had been unknown in England two hundred years before the article was published (1889) is wrong. Shakespeare (1564-1616) mentioned them.
The Washington Elm legend has been debunked, though a thimble from the tree might have existed.