You might try Switch Doctor at www.switchdoctorswitches.com.
The Mesa Boogie switches are at http://www.switchdoctorswitches.com/index.php?option=com_virtuemart&view=category&virtuemart_category_id=25
If they don't have it in stock, they will make it for you. I asked for a specific switch to use the external switch jacks on my amp, instead of the big footcontroller, and they made it at their standard price and added it to their product line.
Brent