Hi Jeremy,
Welcome to the forum.
Webcor/Webster Chicago are grand old names in the history of American recording. Webster built a number of the wire recorders and their art deco looks make them a real favorite in collectors circles (although the proliferation of them on the used market make them a real bargain IMHO).
Here's a link where you can see examples of several Webcors.
http://reel2reeltexas.com/vinListU.htmlI don't know much about the particular models but I don't know of any that were used in the recording industry. Contrary to what a lot of folks might believe, the reel to reel manufacture in the US isn't that old. The first machines that were in production here were by Ampex and they pretty much dominated the domestic market when it comes to studio machines during the early days.
There were a number of manufacturers during the 50's but they targeted home users and the dictation markets.
If the machines power up (Ki is right about using a Variac but it sounds like you already have) and the motors still work, the only major question is the heads. If they're rusted, worn or otherwise useless, the machine probably isn't worth the cost and trouble to restore it. So, the most useful pictures or descriptions you can give us would be of the heads. Most of these machines have a single motor and either it works or doesn't (many of these older machines weren't exactly great when it comes to the transports anyway). The functions are generally controlled by levers, cams and belt/idler wheels. You can usually have the rubber parts rebuilt for fairly cheap and the rest is a matter of cleaning and lubricating. Some felt parts can also be home brewed. It's really more like fixing an old grandfather clock than working on a piece of electronics gear. It can be a real head scratcher if you aren't familiar with
how a tape machine works so a little study will head off frustrations. There's a "Beginners Guide" in a sticky about the General forum that may help but here's a site that has some DIY help for machines closer to the age of yours.
http://www.angelfire.com/electronic2/vintagetx/Follow the links to the DIY section.
Overall, it could be a fun project but I don't think you'd want to bother trying to mix down to either of these machines. That is, unless you have a specific distortion that you're looking for. When it comes to speed variations, distortion and extremely limited frequency response, you'd be hard pressed to find a better machine.