Referring to FIGS 1, 2, 4 and 5 again, the wedge block 3 comprises a wedged base 31, {HEAD ~ two serrated portions} 32 bilaterally disposed near {TAIL ~ the top}, a center opening 33, and two dovetail projections 34 bilaterally projecting into the center opening 33 
Referring to FIGS 1 , 2 , 4 and 5 again , the wedge block 3 comprises a wedged base 31 , { HEAD ~ two serrated portions } 32 bilaterally disposed near { TAIL ~ the top } , a center opening 33 , and two dovetail projections 34 bilaterally projecting into the center opening 33
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH