I'd like to provide the perfect answer, but I don't have one.
If money is a concern, look around and see what you have on hand right now that can work as a make shift barrier. I use old sheets and scraps of materials to become wind driven and visual barriers.
Don't laugh too hard, but when guys come over, I ask them to pee out in the yard. I usually will give them a specific location. On several occasions, I have gone outside and smelled urine (from a predator) in various locations. I have someone pee on the same area. It only takes a time or two before the predator doesn't come back. I don't know how well it will work with the rooster, but it's a start.
Do you have anything that you can make a cage/trap/containment do hickey thingy for the rooster? If he's trapped during the day, then you know he won't be bothering your guys. At night, take him back (carrying him if you can) to the neighbors and say you found him wandering your property again. Repeat.
I understand the desire to let your animals free range. I do. Most of my animals free range and they love it. I have had to be creative in how I set things up to protect them, while giving them freedom.
This is an odd ball option - have you considered feeding him? Maybe he's super hungry. Roosters can get so cranky when they are hungry! Put out water for him? Set up a fenced/safe area for him when he wanders onto your property?
Please let us know what you try and how it works. At the end of the day, please try to find balance.
I am sorry that your drake died. Have a service for him and thank him for being such a wonderful, wonderful friend to you.