{HEAD ~ One flange} 46 has {TAIL ~ a depending lip} 48 and the other flange 47 has an upstanding rib 49 to seat within the channel flanges 40 securing the tray from downward movement 
has
{ HEAD ~ One flange } 46 has { TAIL ~ a depending lip } 48 and the other flange 47 has an upstanding rib 49 to seat within the channel flanges 40 securing the tray from downward movement
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH