I list Caz Smith and Mick Tem's websites and Taplas does the same on paper. Maybe Pluck & Squeeze has something.
cresby.com is not a bad place to go looking for listing sites outside my area. eg RoW (Rest of World - a subtle reference to Mustrad's listing page which says it is the area round Stroud and covers er um the world, or parts thereof)

Caz Smith: lists at least two Swansea Wed sessions, the Beaufort Arms in Kittle is a few miles SW of Swansea but is today. Listed as acoustic - probably music session.
The Buck Inn, Pontlliw N by NW of Swansea T 01792-892294 Post Code SA4 9EF is unspecified monthly Wed session

At this point I stopped looking. Over to you Joe. And thanks for all your work on the Cat.