I often seem to come up against mating disparate shapes, at work, in modelling and building bikes. Every case is unique and involves a good deal of mental rumination sometimes resulting in a satisfying brain fart!
So I have two ideas for this one.
1) Make a short as possible fashion piece to morph from the tea tray mounting area, to the new indicators. I picture this being just long enough to accommodate a nut each end inside, shaped at the top surface and hollow beneath. Maybe the use of a threaded sleeve inside could lend more flexibility to the demand on length? In other words push the treaded stud of the indicator through the outer flange of the adapter then screw on the (custom) sleeve and pick the other end up through the tea tray, with a bolt to hold the whole thing on.
Making a handed pair is always a challenge, but should be reasonably easy using rigid foam, plasticine, clay, plaster of Paris or whatever medium you are happy with to produce plugs for a pair of wee mouldings.
2) This is a little fuzzier in my mind, but involves making a metal (alloy) bracket or bridge that would be sandwiched between the tea tray and number plate holder, or even possibly bonded to the underside of the tea tray? essentially this would feature a down turned ear at each end upon which to mount the indicators. The mounting face would be slightly inside that of the tea trays mounting faces for the original indicators.
The tea tray would then need to be neatly trimmed away to clear the new indicators, forming "wheel arches" for want of a better term.. Not sure if this would eliminate the disparate shapes or make it worse?
I wish I had an old tea tray to donate to this.. I am sure there are one or two around which will become available knowing this wonderful club..
