This fried egg ring is the correct mount for the WW2 Lensatic Sight for the 3" Mortar. I also found a local collector with the upper tube band - strange where this stuff turns up.
Just now searching for the lower band, leather cap and ball end for the tube.
Work on stripping suspension bogies continues (slowly) but here is the bearing for the steering column and some of the restored bits sitting on the shelf.