https://community.logmein.com/t5/Hamachi/Hamachi2-Gateways-Lessons-Learned/m-p/88204#M7567
This is what has happened.
Since gateway network is 192.168.1.x AND the client network is 192.168.1.x, hamachi virtualises the network as 10.40.1.x.
A server/NAS that is 192.168.1.100 on the gateway network becomes 10.40.1.100 on the hamachi client.
Only problem is, I now get Windows "Network Credentials" windows that ask for usernames/passwords and no passwords work. I assume this is because the network drive is 192.168.1.100, but I'm accessing it from 10.40.1.100??
EDIT:
Turns out username was the "Computer Name" found in "System" and password was the account login.