{HEAD ~ The adjustably displaceable frame member} 17 is constituted by {TAIL ~ a flat bar member} 38 having a flat support surface and a right angle rear plate 39 spaced rearwardly of the forward edge of the flat support bar 38 
is constituted by
{ HEAD ~ The adjustably displaceable frame member } 17 is constituted by { TAIL ~ a flat bar member } 38 having a flat support surface and a right angle rear plate 39 spaced rearwardly of the forward edge of the flat support bar 38
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL 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 OTH