This is very interesting and yes this practice is par for the course in downtown Farnham, Surrey on timber framed or timber roofed houses circa 1650. Farnham is the home of the Westminster Hall hammer beam roof framing yard. What I have noticed about this type of roof is that oft times only the lower common rafter is pegged top and bottom with the upper section being simply morticed into place but not pegged. I have yet to figure out in my mind why this is done but I have seen this on many separate occasions and it is unlikely to be an accident.
I like the little ashlar struts between the flying plate and the connecting girt - very medieval.
