While staying at the Witherup House in Franklin PA, I found :
It was published in 1946, when memories were fresh and ISBNs hadn’t yet been invented:
Paging through it, I found a photo similar to one I’d grown up with (clicky for more many dots):
None of those guys look like Dad.
Many of the events in World War II made little sense until the declassification of the Enigma decryptions and the ensuing Ultra / Magic programs showed the value of weaponized math …