Yep, thanks for the reply. I have found a couple of spindle spares & repairs places who are going to contact me after the holiday here in the UK.
The spindle is a rebranded 60,000 rpm kavo 4025, expensive for what it is and probably even more expensive from LPKF, but a very nice piece of kit.

I have retirement looming on the horizon so expenditure on new tools ended earlier this year but I would really like to keep this machine after I eventually shut up shop so hopefully I can get it repaired at a reasonable price.