The message
from John Rumm contains these words:

Dunno - hang on, I'll wander down the garden and look.

Only a tiny shred of label left. Had a blue painted core.

Norton possibly? Their diamond stone cutting discs take plenty of
punishment before giving up.

No, certainly wasn't a Norton. Was a cheapie from the local trade tool
shop. £3, IIRC.

--
Skipweasel
Pay no attention to that man behind the curtain.