horror film (possibly late 70's early 80's?) set in medieval cottage?

[burgundyplum]

I remember a teenage girl, I'm sure it was set in Tudor? Times, servant costume? Locked in an attic, started turning into a devil/Pan/goat?? Complete with hooves?? In a Tudor style cottage/house.  That's all I remember as I covered my eyes and blocked my ears after that!

[Rayo Casablanca]

BLOOD ON SATAN'S CLAW (71) http://www.imdb.com/title/tt0066849/