Look at this list of films by British film company Amicus
The City of the Dead (1960)
It's Trad, Dad! (1962)
Dr. Terror's House of Horrors (1964)
Dr. Who and the Daleks (1965)
The Skull (1965)
Daleks - Invasion Earth 2150 AD (1966)
The Psychopath (1966)
The Deadly Bees (1966)
Torture Garden (1967)
Danger Route (1967)
They Came from Beyond Space (1967)
The Terrornauts (1967)
The Birthday Party (1968)
A Touch of Love (1969)
Scream and Scream Again (1969)
The Mind of Mr. Soames (1969)
The House That Dripped Blood (1970)
I, Monster (1971)
What Became of Jack and Jill? (1971)
Asylum (1972)
Tales from the Crypt (1972)
The Vault of Horror (1973)
From Beyond the Grave (1973)
And Now the Screaming Starts! (1973)
The Beast Must Die (1974)
Madhouse (1974)
The Land That Time Forgot (1974)
At the Earth's Core (1976)
The People That Time Forgot (1977)
Look at 1968- Harold Pinter's The Birthday Party. A strange bedfellow of The Terrornauts and Scream and Scream Again. Why did they do this one-off? The director was William Friedkin who five years later did The Exorcist.
Iain