For my crawl re-creation I applied a matte choker effect to the upper half of the crawl. That pretty much eliminated most artifacts.

EDIT
Oops, little correction: Checking my AE comp I didn't use a matte choker, but I blurred the crawl a bit while it was still at 1920 pixels width (0.6 pixels fast blur) and then re-sharpened it by adding contrast to the (now blurred) alpha channel of the text (Alpha-Levels: input 71/191, gamma 1.0, output 0/255)

Of course I applied these values to freshly typed text that had all the sharp corners of a digital font, and I used the blur (and some more filters, like a Median after that) to make it look more like an optical composite. If I remember correctly you extracted the text from the actual crawl, so it's already "rounded" off, so my values might not work for you.