No, I haven't ever heard of anyone doing the swap with a Corona, but I know it's been done with a Celica. I have parts microfiche for all my cars, and 1st thru 3rd gen Celica, so I'm able to look up all parts and check the interchange. I know that the rear end will fit without a problem, the housing is the same as the Celica Coupe (there's a rear diff cover like the Coupes, not a front drop out third member like the Supra and liftbacks)
I've done all the research on what will work and what won't, just wanted to find someone who's done it to see if they did change the valve or not, and if so how they went about it.
Incidentally, there's two threaded bosses on the left apron of the Corona where the Supra proportioning valve could mount, and when I got the Supra valve I got the front and rear brake line that comes from the master cylinder. It all fits! I checked it this weekend and it's so weird that there's a spot to bolt in the valve, and that the two factory Supra brake lines can be used. It makes it so easy. I would just have to plumb the brake lines after the proportioning valve.
If you're going to attempt the same swap, don't forget to get the e-brake cables, you will need them. I go the whole handbrake lever and everything in between just in case, and glad I did!
For calipers, I got them from Toyota as a reman part many years ago. I don't know if they still sell them, but when I got them I had a friend at a dealership so my cost was relatively cheap. Here's the part numbers if you want them: