I have a bracket from my CBR600RR exhaust I am going to try and make work, going to inspect the boots as well, I am seeing some micro cracks, might just be worth replacing them if they are in bad shape-Someone posted an SLI (3D print ?) file a few years ago to make a little bracket for rear carb support but even a piece of bent strap works.
If they 'fell off' they were not fully inserted into manifolds though. You also NEED some form of fork brace, there is a dramatic loss of stability without one fitted
Thanks for the tip on the fork brace, there was no front fender when I bought the bike so I assume the lower triple tree supported it enough, especially since I see lots of cafes without them. Will do some research on getting something fitted!