The last time I worked with core memories was in 1989.
This was an Air Force Nova 3 computer system decoding and displaying secondary radar information on a radar
screen. (IFF in the old days).

This system was upgraded with MOS memory later (1991-92) and is still in use today !
To load a program we toggled in a bootstrap code to load a papertape from an ASR-33 reader/printer.
I modified this loading of programs by using a 286 PC
and a Procomm terminal program.
All programs and radarmaps were "recorded" on the pc harddisk for faster access and to simplify modifications/upgrades.

DEC PDP-8E's were used a lot i the automotive industry
in welding machines /robotics up to around 1995.

I know about one working PDP-8E still in use today !
It is used in a weighing system i a cement factory.

Nils