Hello Ned,
If you are attempting to get started by aligning receivers, may I suggest going to a Hamfest and talking to some of the folks there.
There are usually used signal generators that you can buy and someone may have some test equipment you may wish to look at.
If you strike up a conversation, you may find someone with equipment they may be willing to part with for very little money. .Even if they do not have the equipment for sale at the Hamfest, they may be willing to dig out some stuff for you. You might even find someone who aligns receivers and has some old equipment they no longer need.
Starting with aligning receivers is probably a good idea.
Here is a link to the ARRL Hamfests, just choose your state:
https://www.arrl.org/hamfests/search That little transmitter you are asking about does look like a "Homebrew" item and may work just fine but it does not have a freq readout that you may need. It is pretty "old school". That is not a bad place to start but there are all sorts of fancy new gadgets. Look around at test equipment before making up your mind. You may wish to start with the "basics" or go with "current technology". The unit you are considering is very much like many old signal generators that have been in use for over 50 years. This includes the IF freq which some old RF generators did have. I think I sold an EICO freq gen for $10, it did work and had the IF freq. It did not go into the FM band though.
At least the seller of your ebay unit provides instructions on using the unit for tuning radios.
There does appear to be an audio generator in the unit....quote from ebay description:
There is a sine wave inside the device with an audio of about 800Hz-1100Hz.
So it does put out a modulated signal.