58w fluorescent on a PIR, with mag-ballast in a utility room.

The tube finally refused to strike up last week, so I installed a
replacement tube, all back to normal now, but I am wondering whether to
adapt it to LED tube or fit an E-ballast. It is a room we often walk in
or out of with hands full, so I replaced the switch with an occupancy
switch (PIR). Once triggered, it remains lit for maybe ten minutes and
maybe comes on three to five times a day - so economy is not a high
priority, so much as tube life. It has gone through maybe three tubes,
in around 20 years.

I am not keen to replace the complete fitting, but I have a small stock
of 3.5w BC LED's. I could perhaps cheaply DIY adapt the fitting, with
4x BC lamp holders.