OK 
Good news
Updating “cec_0000_0000.xml” in this location /home/osmc/.kodi/userdata/peripheral_data seems to have fixed the issue. My Samsung remote is working correctly and Kodi is appearing in my Anynet+ list.
I’ve soft rebooted a couple of times but not risked powering down. I’ll let you know if the issue reappears after that.
So was this file meant to get updated when I edited the peripherals.xml ? Did I do something wrong or is this an issue?
FYI. device_type is now set to 1 in both files.