Indeed, I saw Nightmare Castle a long time ago, time to re-watch it as I dont remember much about it other than Barbara Steele was in it. I'm thinking it was a bit more tawdry than Long Hair of Death if I recall correctly. Will also be watching 'The She Beast' soon...very soon!
Oh...wait...you said 'Castle of Blood' ... darn it all to hell, I dont seem to have access to that film prsently... must MUST FIND IT!