I put the hinge line 6-8" above the bottom. It isn't posed correctly, but there are arms outside the hinge-line:
This is to reconcile the curved valance and the straight hinge-line. The leading edge moves down and forward to match up to the diffuser.
Also I would consider an hinged and extended diffuser with skegs that have skateboard wheels on their tips (else titanium skids for sparks) that retracts up into a half-circular tail
ala Morelli. Per 'D' at Permalink #44.