Transfer a Virtualmin virtual server from one Virtualmin installation to another

We run two Virtualmin boxes in a single data centre. For historical reasons, our email box is a GPL server and our web hosting box is a 'Pro' server. We are setting up a single Virtualmin Pro installation in a separate data centre and the plan is to 'merge' the contents of the two existing boxes into one in the new installation. Because there are plenty of domains involved, there is going to be a lot of messing about with DNS and we are going to have to move each virtual server individually. Are there any tools or plugins or scripts available that might help the transfer process please? Any advice would be most welcome.