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I wouldn't be too worried, chances are the old speaker is going to be useable, they're pretty tough, and even if the paper is a little torn or cracked, it can be patched. Keep in mind that speakers of this vintage were 'paper to the edge' - no foam surround to deteriorate. You can also get speakers re-coned. It's also not hard to replace the speaker with a permanent magnet type.
Basically, in a normal permanent magnet speaker, you have the voice coil which is coupled with the cone via some sort of linkage, and you have a magnet. By sending an AC waveform into the speaker's voice coil, it becomes a magnet in itself, and becomes attracted/repelled from the big magnet, creating movement in the speaker cone which moves air and makes sound. (not a perfect description, I know, but it's easy to understand)
In an electrodynamic speaker like the ones found in 40's radios and the like, the large permanent magnet is replaced by a big coil and an iron core. This magnet coil is connected to the radio's B+ supply, and when the radio is powered, it becomes a magnet. But, this magnet coil also draws current, and makes up a signifigant (well, signifigant enough) part of the load on the power supply of the radio. Without the speaker's magnet coil, or a suitable substitute load, the power supply won't be stable, or work at all.
Now, this is simplified, maybe simplified too much, but I hope it wiil make sense (and that I didn't leave anything important out/give wrong info). I'm not going to get into hum-bucking coils or voice coil impedence etc. Concentrate on recapping the set, take some pictures of the underside of the chassis, the speaker, etc, and we can help you, especially with the recapping side of things. If I'm not mistaken, that set will have "Black Beauty" capacitors. They're just molded paper caps, but they're black with colored bands, and look like really big resistors.
If you haven't worked with electronics much before, and/or don't have a lot of experiance soldering, read one of the many tutorials on the 'net and practice soldering bits of wire or junk components together. The great thing about working on old radios like this is that there's typically a lot of room in the chassis, and most solder connections are just a component to a terminal strip or tube socket pin. It's pretty easy to get the hang of. You don't need fancy equipment, a 30 watt Radio Shack soldering iron will do just fine. A soldering gun is handy too, for larger power supply connections and the like. There's nothing static sensitive in a tube radio. A lot of the tube sockets are phenolic or bakelite, and don't melt. Sure, too much heat can damage components, but not nearly as easily as working with modern digital logic and plastic connectors. Just be careful around the coils - the delicate tuning coils and the like, they're mounted in the squarish metal cans. You don't want to disturb them or melt them. Chances are that there is nothing wrong with them, I've never encountered an open coil. If you leave them alone they should be just fine.
Keep asking questions, it's the best way to learn. And it gives people like me a chance to ramble on about electronics... We're here for you, always more than happy to help. We all learn in the process. I'm by no means an expert. I've never had any "real" training in this or anything really. What I know I've learned from reading, taking things apart, fixing radios, and talking to people. I've restored several radios and televisions, but I get stumped once and a while too. With AK, there will be someone else that can correct me or give me insight into something, and it helps everyone learn by reading the posts.
Most importantly - have fun!
-Ian
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