Quentin: "The (presumed) adjustment wheel is rusted to the bolt. It & the bolt turn freely, but don't seem to do anything. Does that mean the threads are stripped where it goes into the blade? "
The adjustment wheel doesn't thread into the iron (blade). If it did, the iron wouldn't be able to be adjusted. What adjusts the depth of cut (by moving the iron up and down) is the yoke that pivots as the wheel is turned, thereby moving the iron.
If the adjustment wheel is turning, but not doing anything, check to see if the blade is rusted to the frog, or see if the yoke (looks like a spur that sits over the adjustment wheel) is not frozen. The blade (iron) should move up or down as you turn the wheel.
I've read a lot about Stanley hand planes (I have several, including a couple of Baileys, as well as an old Millers Falls). If you want to do some reading, I suggest you check out this site: The Superior Works - Patrick's Blood & Gore: Preface
My Stanley's all have markings on them. The plane number (size) is behind the tote and the name, either Stanley, or Bailey, is in front of the knob and the lateral adjustment lever usually has "Stanley" stamped on it. I don't see any markings on the plane in your pictures, so I'm not sure it's a Stanley.
Since you only paid $3, you could spend some time restoring it - if nothing else, you will learn a lot about the process and the plane. You might get a decent user out of it if that is what you're looking for, but I don't believe that plane to be worth much (sorry