Change For A Half Dollar Anyone?

Very Spiffy!

So could they only be used for stamps back then?

Oh and I'll give you 2 Quarters for it...plus a tip!

I was hesitant to get into fractional currency until I knew how to discern fake from real. How often were these counterfeited?

I LOVE the fractional currency! I've been collecting them for about ten years now, and probably have 12 or 14 different ones.
Buying U.S. paper money is always a good idea as long as the bills aren't damaged or heavily worn.
Any quality undamaged piece of U.S. currency whether it be a fractional, continental/colonial, or large sized note will be a good investment. There just aren't that many that have survived, and the popularity of collecting them just keeps growing.
I usually look for higher grade fractionals like EF - AU or so.
There are many surprisingly affordable notes in those grades.
I pay in the neighborhood of about $50 for nice fractionals. The scarcer ones will cost more, but about half of the issues could be had in higher grades for $50 or even less.
When I buy these higher grade notes, I'm usually buying from an established dealer at a show. I definately want to see and hold an old note before I plunk down a lot of money for it.
I don't worry too much about counterfeit fractional notes, because I usually buy from knowledgable dealers, and I don't think the fractionals have been counterfeited that much.
If you're just getting into collecting fractionals and want to make your first purchase, then you can find some of the more common varieties in heavily worn condition for cheap prices, under $10 even. Maybe even $5. Just stay away from the notes that are torn or heavily stained, or that have holes through them.