So, I couldn't get the MODO Drum 1.5 working, and after reinstalling several times (to differing locations on my Win10 machine), checking registry entries, and reading numerous issues posted by others in a similar situation, I tried this:
I went to the settings (cog wheel) in the UI and removed the '\MODO DRUM' from the end of the path (so my 'V:\MIDI etc\IK Multimedia\MODO DRUM' became 'V:\MIDI etc\IK Multimedia\'), closed the settings box, and it rescanned the folder and found my missing (only/default) kit. However, there were no sounds at this point, but restarting the DAW, and hey presto! I had a working kit. Sounds good too.
No idea if this fix will for all, but I thought I'd post this up to maybe save someone else some stress.