You haven't actually established that these birds are overweight. They are both large heavy breeds and could easily be normal build for their strain/cross. I've had HUGE Orpingtons and RIR crosses in the past.
The bumblefoot could be the main thing that is hindering their mobility. They must be in terrible pain not to be able to run away from a rapey rooster. How bad is it and what are you doing to treat their feet? Please post feet pics.
They could easily be elderly if they aren't laying, or have internal issues such as ascites which has been mentioned, and which will need treating. You haven't replied as to what their keels feel like, or whether they have water belly.
You also say you love them like family but talk about them as fat ugly and old

. I'm a bit confused at that.
My flock free range, and have treats and leftovers and don't get fat. I never restrict their food. Chickens are mostly self regulating weight-wise and rarely need to be put on a diet. Why do you think they are too fat?