There are two approaches to controlling Allen stops to my knowledge, at least without doing extra modifications to every SAM's driver board (Artisan). Zuma Group has a replacement for the Allen capture board for consoles which remain playable with their original electronics. I have a free design that is intended for stripped down consoles.
The reason generic decoders are not appropriate choices is because of the higher voltages but more importantly because rather than operate a single SAM at a time, Allen pulsed a whole division at a time whether or not individual stops needed to move. This makes a decoder solution impossible without major rewiring or else using the Allen's own capture supply with its five individually switchable outputs which need to be controlled by the decoder. A control line to each driver board is set to determine whether the stop will turn on or off. Then the decoder pulses one of four capture supply inputs which sends a 50V pulse to an entire division's SAMs. This allows a simple CMOS control signal through a 1.5k resistor to operate the stops -- the usual hefty driver board isn't required as the drivers are on the individual SAMs. It is a nifty arrangement which requires a specialized decoder.