On my Anscoset ll, the letters A-E coincide with the flash guide table attached to the rear of the camera door. In case yours has fallen off (they're only glued on):
A-strobe X-more than 7 feet
B-Anscolite AG-1B, 7 feet or less
C-Anscolite AG-1, M2B, 6B, AG-1B
D-M2.6, AG-1, 5B,25B, M5B, M25B
E-5, 25, M5, M25
C,D,E are all varieties of bulbs
Hope this helps and you get plenty of use from your Anscoset. By the way, your camera is made by Minolta as you probably guessed by the excellent Rokkor lens.
The ten second rule is a little different at my house. When there are ten seconds left in an auction, it's time to fire off a bid.