The new SDP is very eurosceptic, from their own website:
"Brexit was a victory for democracy and accountability over lobbyists and bureaucracy.
The Social Democratic Party has a very positive vision of Brexit and, for that vision to be realised, we must ensure that the powers returned to our elected representatives are used to benefit society as a whole, rather than merely elements of it. "
They also lost their last councillor a few years back to UKIP: and at this point I'm pretty sure they were just a label that random local councillors in Port Talbot used to get elected...