Its a simple servo pushed the trigger arm out of the safety notch on the tube, the spring pulls it back into the launcher and fires a .22rf blank launching a spigot dummy for the dog to see and retrieve! Fairly realistic training!
If you just wanted to stand a few feet away you could just plug in a servo tester, but Im assuming you want to be much more remote. Any Tx/Rx outfit that drives servos rather than a circuit board will work. Should be doable in evilbay for around £30 I would have thought. I'll have a look in my spares box to see what I have. If I don't need it you can have it.
It is indeed, it would be nice to get a simpler unit but that would require customisation. I know the servos have a lifespan as the early versions lasted about 3 months before needing replacement but I assume now 10 years on they have sorted that!
Ideally a little transmitter with a single push button would be cool!