Reverend Rob
Posted September 11, 2018 - 2:29am
The 10AB is from the FHF 324 ebauche, as is the 10AE, 10AM, 10AN, 10AR, 10AW, 10AX, and the centre sweep versions. Some of these exist in all jewel versions, like the 10AE and 10AN in 7, 15, 17, and 21. There were all USA made versions like the 10AX as well.
It is very likely that the 10AB was made with higher jewel counts also, because all of them had more than one configuration/jewel count, although I can't confirm this.