Welcome to the lighted sections of the site, and yay for delurking with a map!

You may find that running some noise filters on your lines and color (gimpressionist, tiny (2px-ish) blurs and spread filters are my favorites for this) will give it less of a computer-perfect line/color look. Also, one reason it looks so modern is because your font is so modern. Try hitting dafont.com or another free font site and looking through the Calligraphy/Script sections for a nice Antique-style font that matches your mood. It makes a world of difference. Another thing that might help is to take the smudge tool at a pretty large size and smudge the strokes of color around your borders so that they blend more like paint.

The last thing that I'd suggest is precisely what you've done -- a parchment or other textured background also helps relieve the modernity.

Still, even if it's not what you were trying for, it's pretty cool!