Here's a website that has the lever locking kind. You can contact one of their dealers. Bare Co USA - Shaft Guard
Problems with these things are the reason mine is rolling around in the back of my truck.I know you are supposed to maintain the guards for safety, but as dangerous as pto shafts are I think the best rule is to not get around it while it's running. I also don't understand why a replacement guard costs over $100, they want people to use them they need to make them reasonably priced