No idea of id, but the rule with Clematis pruning may be simplified as Flowering before June, don't prune. Flowering after June, prune in February.

I know that's the advice but I had what looks like a Nelly Moser, which grows in a pot on my terrace and which flowers in June/July and because it's south-east facing, goes all brown and crispy. I cut it down to the ground a few weeks ago and put the pot in the north-east side of the garden and it's nearly grown the full length of its support hoop and looks for all the world like it's got buds about to mature. I give up with the official pruning!