1970 COMPASS-
WHITES SILVER EAGLE-
WHITES DFX, 4X6DD COIL, 6X8DD COIL, 950 COIL, 10X12SEF COIL-
GARRETT PRO POINTER AT, GARRETT AT PRO , MINELAB EXPLORER SE with 8.5x12.5 Cors coil
It looks a lot like the linkage that engages the mower blades on a lawn tractor. My 15 Hp Craftsman has something very much like it between the mower deck and the frame/seat area.
I can see one falling off a similar machine.