Hi Jijo
I'd looked at those. It turned out that my snmpwalk command was missing the mandatory level option!
So for anyone looking later, you can use this command to snmpwalk the switch once you have configured v3 as per the examples in Jijo's link. This proves you've done it correctly!
snmpwalk -v 3 -a MD5 -A password1234 -x AES -X password1234 -l authPriv -u admin2 x.x.x.x