[Nutbutt]

Looks like a solid product ! The Mighty Mouse has its check valves mounted right on the can and could do a dual vacuum outlet. The problem with using the separate check valves is that having them situated away from the can oil will start to build up on the valve and will need to be cleaned every so often. I don't know of any can that cleans the oil vapor completely (sorry all the can makers). Having the check valves integrated does not have this problem if they good quality metal valves.
I am interested on how your old setup may have caused a hydro lock ?