That is a beautiful e-missal! Have you done the propers?
I've been thinking about this, and I may have some perl code that could be adapted to provide this content. On the webpage, the "Liturgical Calendar" functionality could be adapted to supply the propers in much the same way it now forwards to Goffine's Devout Instructions for Sundays and Holy Days.
Would you have an online source to recommend for the content, or, if there is a hardcopy source that is preferred, could you suggest the title so I might procure a copy (I have a hardcopy library for most of the content, but it is packed at the moment as I am between homes).