Werner's tool is called a Knowlson spring spreader. They show up on eBay occasionally, I think there's two up now. There's a similar tool called a tomahawk spring spreader that actually integrated a tube of grease into the tool handle. These are often associated more with Model Ts.
I should note that you can also get excellent results with a pair of flathead screwdrivers and a hammer. Here's a thread I started last year regarding this operation:
https://www.fordbarn.com/forum/showthread.php?t=268039