!970's, i was still using those well into the 1990's or even later.
Roller towels, wonderful things until they went wrong and dangled in the toilet bowl.
I was doing some tidying the other day and found my key ring with about 7 different towel cabinet, soap dispenser and toilet roll keys along with 2 different fire alarm testing keys. Along with a couple of keys I have no idea what they did.
We were very versatile us security officers.