I ran across this and thought it looked interesting. I found some info from Atlas about this great, new product, but that’s all I found. Nowhere can I find them in stock or much evidence that anyone has used them. Did these make it to market before Atlas had to switch manufacturers? 
http://imageshack.us/photo/photo/441/57switchcontrol72dpi.jpg/ Sorry, here’s the right picture
They are not listed in the Atlas Catalog or online store. Googling it, results show availability in 2011. You may have to contact Atlas for a clear answer.
I queried Atlas by email as to availability and price of the #57 switch controller. they promptly answered today (5/14/13) with this: Will be available in 2-3 weeks (about 6/01/13), with an MSRP of $14.25.
I’ve seen them listed as low as $8.99 (Model Train Stuff), but not in stock.
They had been recalled because of a faulty internal screw that caused the controller to short out when the push button was depressed. That problem has supposedly been fixed. I did recently see an original one on a local layout, and it works very nicely. The layout owner had to open it up, file down a tiny screw to make it shorter, and reassemble the box - no more problem.