Hi Mike, I too love old machines. You definitaly want to check out
www.owwm.com all about old wood working tools
Those old craftsman cabinet saws are super rare, not to mention the parts for them. Best bet for parts is the owwm site, or ebay.
Personally I don't think you will need a blade guard. I don't use or like them. Blocks too much of the blade for visual reference. The best blade guard is between your ears.
You will however need a riving knife, similar to a splitter, if you plan to do quite a bit of ripping on the saw. I don't know what kind of attachment points you have available on that saw, but you will probably have to make a custom riving knife to fit that saw.
Have fun and be safe. If you just got the saw, you probably want to change all of the bearings. Even if the saw appears to be unused, the bearing grease will dry up over time and cause the bearings to seize. Which could in turn score shafts and housings.
Please post a picture of the saw.
Here is a link to the 1957 Craftsman catalog. I could not find a manual, at least quickly.
http://vintagemachinery.org/pubs/222/4403.pdf
MPOWERED, those are actually called blade inserts. I THINK the OP is talking about a blade guard which floats over the top of the blade on springs. The old craftsmans usually had an integrated blade guard / splitter unit.
There are 3 things that have to deal with the blade on a table saw.
Blade insert
Riving knife or splitter
Blade guard
Mike which parts do you need?