One good source for engraving tools etc is: http://www.2linc.com/engraving_software ... _fonts.htm
. they have diamond pointed tools and spring loaded engraving holders. I have purchased most of their tools at some time, they are good quality, but they are somewhat pricey.
One error many people make when trying to cut glass is doing multiple scores..... you only ever do 1. if you do more than 1 you are VERY lucky if the glass breaks where you want it.
When i was doing stained glass years ago, I would make my score on the glass then tap lightly from the bottom with a metal tool, piece of round 3/8 steel rod works, but something with a very small contact point. Doing this carefully, most times you can 'chase' the crack in the glass all around your profile - sometimes not. If the crack goes off on a tangent, as long as it doesnt go through your part..... let it go and break it off, but this is where a glass grinder comes into play. Pretty much no way around inside curves without grinding. However, as noted previously a good idea is to divide the shape into multiple pieces and make it into a stained glass panel. It will still be just as impressive.