Who Asked This Joker
Uchelwyr were from all over Wales, not just Gwynedd – land owning class – lords or noblemen.
Not sure why you think the figure NCS posted looks to be particularly Irish influenced? Is it because of the green? The Welsh are quite often recorded as appearing in green and white (later Tudor colours as well), so no Irish influence. There would of course have been interaction with the Irish, both as allies and raiders and no doubt with Manx and Scots too, and definitely with various nordic types coming down through the Irish sea, so the ‘celticity’ would be a melange of current fashion and armour from many sources, including Anglo-Saxons and Normans.
The Scots Thane looks as good as anything else suggested for the early period. I’d be surprised however if many (any?) Welsh noblemen turned up like that in 1260.