Propane Stove 5400A issue

[msangler]

Nice forum here and hoping you can help me with an issue. I rebuilt my stove as it was leaking propane into the chassis (and igniting so that the chrome top got hot enough to boil any liquid that spilled!). I removed all of the rivets, replaced the needle valve washers, cleaned off years of gunk, painted the exterior red and reassembled the whole thing. On the test bench, without the chrome top, it was fine. Fully assembled, it still works great but I am getting "blow-by" of flame under the right hand burner bowl. When I look at it from the side, I can see that it is slightly higher at the back (where the flame is showing up) than the front. There is no gasket in any drawing I have found and there are 3 small nubs on each burner location to keep the burner bowls elevated. Beyond that, I cannot see what is out of alignment. At gas flows for simmer and a bit higher, everything is good. It is at the higher volumes that the blow-by occurs. Thoughts?