Does the volume compare and contrast different sections of the Liturgies most commonly used in the churches and answer the theological questions involved?
The work primarily focuses on issues of significant difference, and does indeed answer any relevant theological questions when necessary, though it seems more concerned with historical issues (i.e. questions like, "when, where, and why did practice X originate?"). The work is ultimately quite short (just over 100 pages) and so it is not an overly thorough treatment of the issues in question.
How do the anaphora and epiclesis in the Liturgies compare? Are different theological apects emphasised?
The epiclesis is not even given a mention, so I assume Fr. Ishak found there to be no significant divergence to discuss there. With respect to the anaphora, his observations aren't particularly interesting . He simply notes the great divergence in number and attributed authority, whilst making a brief remark that in spite of those facts, they all appear to be theologically sound.
It's interesting to note however, that this work really highlights the diversity of liturgical practice within the OO Church itself. In contrasting differing liturgical practices, Fr. Ishak often divides his discussion into the categories of: 1) Syrian, 2) Ethiopian, 3) Armenian, 4) Coptic, and 5) Byzantine.
I will see what I can do. Our Church usually has no problem with uploading anything and everything onto the internet, so hopefully there shouldn't be a problem with pursuing your idea (except that I don't have a scanner, for now at least).