I think I have it figured out. Okay listen careful (well read careful.)

One full rotation of the standard elevation motor matches the timing of the mato sherman firing sequence.

I have taken an old elevation motor assembly and positioned two micro switches at the 1 degree position on the case of the elevator. When the fire button is hit the motor rotates at just about the right time or the 359 degrees position to close the micro-switches. The high voltage flash is triggered as is the sound module.

The elevation motor and micro-switches are then housed ithe rear of the lower hull.

I post some pictures of this contraption soon.

Don