I wasnt sure what I ordered way back when, but I just checked my order history at mcmaster-carr and I definitely ordered 1x1 angle.
I know I had to grind a little here and there to allow the hatch to sit flush, but not much.
I also re-cored the hatch while it was out, but I don't think that changed the depth at all. If I recall it fit pretty good.
You could probably get the 1 x 3/4 angle and not bother with the grinding.
http://www.mcmaster.com/#8542k66