Well I suspect they're chronologically too far apart &for different purposes, tho the outside architecture looks like it may be similar.
I've been to Tudons & inside it 'feels' quite chambered tomby - a bit like some of the ones on Rousay, esp the 'double-decker' Taversoe Tuick http://www.themodernantiquarian.com/site/398 tho much more cramped.
What's the inside of the Irish building like 4W? It looks like it'd 'feel' quite 'housey' but difficult to tell.
love
Moth