This Leslie is basically a 122 with an 11-pin interface. This allows Hammond to conform to the UL standards that eliminate running AC power through the Leslie cable. (Older models are grandfathered)
Hammond Suzuki makes a kit (1174) to connect this Leslie to your A-100. All Leslies normally need a kit to connect them to an organ unless the organ provides a Leslie output. You would be faced with buying a kit no matter how many pins you have unless you intend to build your own. There's no reason building one for an 11-pin would be any harder than building one for a 6-pin. In fact, the switching on a standard 6-pin Leslie is more difficult to provide than the 11-pin.
I say get the Leslie if it looks good as that is a good price. Go ahead and buy the kit (1174) as it will provide all the hardware for switching speeds and main/echo switching.
George
Organs
Hammond B-3/145
Hammond Super B (MIDI Controller)
Yamaha FX-1 - TM-1 x 2
Synths
Korg Triton Pro
Yamaha P-80
Native Instruments Soft Synths;
Akoustik Piano, Electrik Piano, B4II,
FM-8, Pro-53, Massive, Absynth,
OPXpro, Mtron