NY wrote:

Were CFLs available as long ago as 30 years? My impression is that they have
only been available for about 10-15 years

I bought some before I moved to this house, and brought them with me 27
years ago, I think they were a year or two old by then, and I didn't buy
the Philips "jam jar" SL*18 version which preceded them, they were
expensive enough back then that I wasn't going to leave them behind.