Do you mean this one?
We must have different definitions of what drape is in a coat, because that one has none from what I can see. It needs a bit of work IMO, more room in the chest and waist (no offence to the owner). I think an un-lined coat, unless in very heavy fabric can't really get much, if any drape. It simply isn't heavy enough and that's where the canvass comes in.
Trousers look great however.
To me, that DB is too tight... in much the same fashion as most of the DBs I see on #menswear blogs these days.