Definitely give them a few weeks to recover from being fixed, and let them live close, but not close enough to bite, for a few weeks. I had my 2 cages 6 inches apart for the first few weeks. That was after my female attacked the male. Left 4 open wounds. After letting them get to know eachother, I found it easiest to do a bunny smoosh. I put them next to eachother with someone else helping me, kept stroking them, for 10-15 minutes at a time, every day. My little male is still nervous. So yes, those memories are long. But no intros before a few weeks of being able to see eachother. I can now have mine in a small pen for 4-5 hours, with me checking in on them periodically. I’m npt yet at the overnight part – because she doesnt’ let him move freely. But they snuggle alot. So it is possible, even after a serious bite. But it will take lots of patience on your part. You need to create an initial environment that Ruby will feel he is not in danger. Make them positive sessions. Look up bunny bonding techniques on youtube. there are 6 videos. I found them helpful. Oliver scratching at his cage – he was trying to get to Ruby all along. You’ll know that it’s time to start a bunny smoosh (or car ride), when Oliver is using his litter box again. Initially, he will stop using it, and mark (poop and pee) everywhere, especially at the side of his area that is closest to Ruby.
I must say – I have never bonded 2 males. I’m on my 3rd pair of male/female. Each rabbit is different – and one of my bunnies is on her second bonding, and it is much harder than her first. Read a lot, look at other peoples bonding posts, find something that works, and stick with it. Go slowly.