member 70 such that the hard material forming the lock mount 76 does not contact a wing positioned in the cradle 20 stated differently a portion of the cushioning member 70 is interposed between the lock mount 76 and a wing clamped by the front clamping member 24 the lock mount 76 may include a back plate 80 and side plates 82 extending outwardly from the back plate 80 the side plates 82 may secure to the back plate 80 by means of screws bolts welds or some other fastening means in some embodiments the back plate 80 and side plates 82 are formed from one monolithic member such as a channel or rectangular tube having one wall removed in the illustrated embodiment the side plates 82 secure to the end plates 68 by means of rods 84 extending through one or more of the cushioning members 70 and secured to the end plates 68 and plates 82 by means of fasteners 86 such as star fangled nuts or some other fastening means one or both of the end plates 68 and side plates 82 may define an aperture 86 for receiving a pivot 26 such as one or more pivot pins 26 extending through the apertures 86 and the apertures 66 of the rear clamping plate 22 in some embodiments a bushing 90 extends between the side plates 82 a rod 90 may pass between opposing end plates 68 and pass through the bushing 90 as well as the side.