UPDATE -
It happened again earlier and I spent over 1 hour cleaning and taking it in and out of the case. PITA and not what I needed in thge middle of a huge R&D project. I had to give up.
Then after a few beers I decided to go at it again. So armed with a roll of masking tape and some cloths to keep sparks out of the rest of the machine I fired up the angle grinder. I am like a surgeon with this thing.
However, just before my first incision I picked up an empty beer can and cut a long strip out of the side. 3mm wide.
I then used this from the front to go under the carriage of the linear bearing and low and behold, chips for days!
So, chips cleared and Im up and running again. result.
Now to step away from the gfrinder and have a well deserved rum. PocketNC, you have my address, send rum and a new L bracket. Cheers.