Thank you all for your replies.
Tom, I last spoke with Mr. Bier last May, which was after the posting that you referenced.
Randall and Scott, thank you for pointing out that a "period-correct" radio for my 1962 TR4 would have been AM-only. In fact, that is what was installed when I bought the car in 1965. However, my car is a daily driver (at least during the twenty-six days per year when the car and I are in the same state). So I just want something that would receive FM without looking completely out of place. (When I wanted to receive FM in my entirely stock 1954 Chevrolet Bel Air during the 1970s, I hid under the dash a Radio Shack converter that provided an AM output to the stock radio and that I powered by dividing down the 200-volt plate voltage of the six-volt radio. I don't think that such things are made any more, however.)
And Rusty, thank you for the link to the auction. I am hoping to find a cleaner-looking one than that, however, which Mr. Bier had promised to supply.
As for the stock location of the speaker, the one in my car's original AM radio was mounted in the bottom of the radio's case.