Many years ago I started a cross reference list and have many things listed (headlight buckets, tail lights, steering wheel hub, etc) but it is by no means an exhaustive list. Unfortunately, it does not help with the current part I am looking for and maybe its time to take the broken one to the local Moss shop and see if it matches a TR3. As for improving the completeness of the list, I am always willing to undertake these things and can add to my existing list if anyone has input. I have also been contemplating creating an Ace web page and making this as apart of it, but have not yet tried to pull one together. I'll try and post the list I have and if anyone wants to provide their info, I can add it in. Also, many years ago I saw an Ace cross reference on e-bay that showed many mechanical cross references (1953 Studebaker clutch disc could be used on a AC engined Ace as an example) and so if anyone has a copy of this manual, it could add a significant amount of info to any future list.
Jay