I have a brand new Retro-Tec DM2 that may work for that. I've never used it, but then again, no one else has either.
I do have an extra fan speed controller that is identical to the one in your picture. It is used but still works very well. Also, it is an older model that does not have a built-in cooling fan.
That's great Eric. What would you ask for it? You can email directly at firstname.lastname@example.org, if you prefer.