A few thoughts Russ, I'm guessing that that is an early version of an electronic relay probably some kind of safety interlock.(found a 77 Aspen diagram that has an interlock)...
If its still functional & most of the "flux" is still in tact seal it with something like Plasti-Dip. Hopefully someone can make a correct ID but funding a replacement may be futile.
think I found it at Rock Auto STANDARD MOTOR PRODUCTS Part # EGT3 {EGR TIME DELAY SWITCH}