CatBus said:

The fonts used on the theatrical subs cannot be recreated using any existing font--they need to be hand-modified in Photoshop, so a straight SRT-to-subtitle conversion is simply impossible if you want good-looking results.

Well, this is not entirely true. Has the original on-screen subtitle font been identified? It will likely have been a photo-film font supplied to Lucasfilms. I can supply a digital font that can be used if a consensus of the original font name can be supplied. Drop shadow and 'stretch' included and everything.