Both the 10AN and the 10AE are from the FHF 324 ebauche. As was customary, Bulova either modded the balances or produced them from scratch, usually in the US. In this instance, the 10AE has a different pallet arbor, a slightly different balance, and a slightly different mainspring. Intermixing parts could be problematic, but this is true of almost any of these movts. (Except, of course for the approved interchangable parts) Since the overall size is identical, it would have been common to substitute one for the other during repair, depending on what the issue was. Water incursion was the most common problem that could almost guarantee the destruction of the movt. Swapping the movt would have been common, especially once the watch was well beyond warranty.
Both the 10AE and the 10AN came with 7, 15, 17, 1nd 21 jewel configuration. 17 jewels is a fully jewelled watch, right to the centre, while 21 jewels usually denotes cap jewels.