In the preferred embodiment, the first pivot mount 40 is formed with {TAIL ~ a pair} of {HEAD ~ side walls} 47, 38 and a back wall 39 rigidly secured to and extending between walls 47 and 38 
In the preferred embodiment , the first pivot mount 40 is formed with { TAIL ~ a pair } of { HEAD ~ side walls } 47 , 38 and a back wall 39 rigidly secured to and extending between walls 47 and 38
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH