I can't comment on the flyability of the Byron but I do have a Great Planes version which weighs in at about 18.5 pounds and is powered by a O.S. 300 twin which is plenty of power and the sound is nothing short of phenominal.
As with all Christen Eagles with that short coupling, landing is a tense moment but generally it flies superb when it's in the air.
A friend of mine bought a half built Byron from a hobby store and finished it, glassed it and covered it with low temp covering I think, flew pretty well on it's maiden but since this was his first excursion into large planes he was a bit nervous which caused him to land into a field which didn't do too much damage. His second attempt he got airborne too quickly and stalled the plane shortly after takeoff, it rolled and crashed into the field, he currently has it in pieces and hopes to rebuild. This version was electric powered and I think his came in around 17.5 pounds. If you would like to hook up with him and have him answer some questions I can sure send him here.
By all means you need to keep this plane as light as possible, go easy on the glass and paint if that's what you use. The 2.1 Moki would be a great engine for this plane, you would want a minimum of 50cc if going gas.
Mine has 17 flights and sits comfortably in my living room as a show piece.
These always draw a crowd and the flying stops when you get it airborne. Good Luck on your rebuild