I have done quite a bit of stained glass work. For smoothing the
edges I use a Glastar grinder, but also fine tune any ragged edges
with a carborundumstone—referred to as a carborundum file. For the
small amount you have, it will be a very effective, less expensive
method, than investing in a grinder. Every glass store used to carry
them but for some reason, they are hard to find. I was able to get
one recently from Alpine Glass http://www.ganoksin.com/gnkurl/ep7zbs
Item 2007, price $7.95. It should be just fine for your purposes.
Why my interest in stained glass? My house has an ugly cyclone fence
running along one side. I decided to make a lot a stained glass
panels to hang on it, and now it is delightful to look
at—especially when the sun shines through the glass. My neighbors
were delighted, andI can now enjoy the fence, rather tha=n shuddering
each time I look at it.