First off, it's an easy "push button" fix at your transmitters for reverting your new purchases to the more robust "RF1" scheme of frequencies that are loaded into your existing gear.

(F.Y.I. a discussion of the relative merits of both schemes can be found here: http://line6.com/support/message/374285#374285 )

In my opinion, downloading the V75 instruction manual pdf is the quickest and clearest way for you to learn the simple push-button protocol for switching the later firmware enabled transmitters back to RF1, ...plus it'll give you details of the additional features that have arrived with your fabulous new acquisitions.

You'll find it here: http://line6.com/data/6/0a06434d1562550088eb0c05de/application/pdf/XD-V75%20User%20Manual%20-%20English%20(%20Rev%20B%20).pdf

Incidentally, it's an absolute requirement that all XD-V systems be operating in the same RF scheme (be it RF1 or RF2) when working near each other, ...which could just be the source of the grief that prompted this discussion. 

I'm confident that you'll shortly be enjoying the new "toys" as much as I do and that your enjoyment may even prompt a visit to a Line 6 stockist who may possibly be "sweet-talked" ("...If this works, I will definitely be back to buy everything else in your store..." etc. etc.) into allowing you an online hour or so with a V75, which is all you'd need to upgrade the firmware, thereby gaining those features for all of your gear.

All the very best from "down under".