each other via a pivot or support means 13 in the illustrated embodiment pivot means 13 comprises a fastener e g a bolt or support fastener 15 disposed through an aperture 16 formed in both first 10 and second 12 members and secured with an adjustable locking fastener 19 e g a wingnut in such a fashion the first 10 and second 12 members are relatively moveable in at least one plane moreover the relative position of the first 10 and second 12 members may be adjusted by loosening or tightening pivot means 13 in a conventional fashion first stationary member 10 may be affixed to or integrally formed with an attachment assembly 8 which generally comprises a stationary member 31 and a traveling member 21 traveling member 35 is generally u201c l u201d shaped in configuration and defines an upright portion or traveling upright member 43 and a tongue or traveling plate 38 as illustrated stationary member 31 also describes an u201c l u201d shape and includes a stationary upright portion 37 and a stationary base 34 where said stationary base 34 defines a slot 35 sized to receive traveling member 32 the stationary upright portion 37 is joined to and extending orthogonally from the stationary base 34 as shown in fig5 the stationary base 34 has a pair of spaced apart legs 11 as clearly shown in fig2 each leg 11 has a free end 14 and an inner surface 18 with a channel 17 formed therein in such a fashion traveling member 32 is adapted to be slidably received within support member 31 the stationary attachment member 10 is joined to and extending from the stationary.