Hi Pete,

I made a smoke pump using my old Ram 500 fuel pump and a Kontronik Rondo 300 Speed Controller. It works great and looks like it might be a direct replacement for the one in your picture. I bought it from Tower at the time but they no longer carry them.

Using Google I found the following:
<span class="serp_results_site">http://shop.singahobby.com/?q=node/27445</span>

Here's a good source close to home:
http://www.icare-rc.com/motor_controls_brushed.htm

Regards,
Joe