Well, it took a bit of reading and messing about, but I am posting this to the forum via mesh! I set up a single node several days ago, and a second node today for experimenting with connectivity. First test once they were both up was a DD-WRT WiFi access point connected to the second node, from which I could then access both mesh nodes. Now in the interest of further testing I've temporarily connected my original node to the Internet. Assuming I can still click "Submit" it seems to be working well.

Now on to getting some decent antennas set up!