I was under the impression that the 1st appeal was purely on non qualification, not on catchment, but I would hate to pass on the wrong advice.
You are absolutely right - the panel will not give a moment's thought as to whether a GS place would be available.
I'm also assuming they would still need the support of the headteacher, which is a little more tricky as our school ( being a feeder for our local comprehensive ) is not really supportive of all things 11+.
Panels are not unfamiliar with heads who are anti-11+ (not exclusively an OoC phenomenon!). In this situation parents have to assemble as much academic evidence as they can.http://www.elevenplusexams.co.uk/11plus ... rs.php#b11
The school, by the way, can be legally required to make available any academic information they have in their records.