Darren,
I cannot find a picture of it but it seems to me it was a bracket that was cupped on the top to fit the contour of the back of the tach housing and the other end was concave to fit to contour of the steering column. I kind of remember it being held on by one large nut in the center using the large hole you see on the back of the housing and was also chromed. This bracket was in turn held onto the steering column with a very large hose clamp. I see photos of these all the time but cannot seem to find one for you right now.
Apologies if my memory is wrong.