Thanks Marc.
You can see from the attached dark subtraction from the image that the dark frame noise (shown as dark red groups of pixels removal) only removes some of the noise with which it lines up with perfectly.The other bright spots are single pixel spots all over so I am not sure what they could be.
I have asked for a quote. They are now called Palmway Optical,
info@palmwayoptical.com
I am not sure I would do this due to the palaver of getting the mirror off the glue to the support and then getting it all back in the exact same location to match the corrector. The secondary also should be involved which would be another headache.
Good to know it could be done if required and could be still much cheaper than another second hand scope.
Can dust or condensation cause bright reflection points? I could look more closely at the edge as you suggest.