Go to
www.jjc-electronics.com
I have his triple expansion steam recip engine linked to a slave telegraph and steam whistle unit. Just for kicks I connected it through the hi-fi and set it off with the radio while I was upstairs with the missis. Scared the life out of the missis!!
He is also a very nice guy who is very helpfull but he works away a lot so you may not get an instant response. His wife is also very helpfull and must be well used to dealing with the likes of us by now.