Thanks Hank

I see interest in this thread appears to be waning, so unless anyone has any onward questions I'll make this my closing post.
Last night I had a go at de-burring the scratch as pictured earlier;

The record (Rainbow On Stage) was bought in my early teens, I failed to check one of the sides of this double LP.
The track in question (Still I'm Sad) was briefly played on a very modest TT at the time, but after a succession of loud clicks and occasional skips the arm was quickly lifted and the track never played since.
The scratch got the treatment (while spinning The Yes album

) and after over 30 years in my possession, this track finally got a full airing

Not perfect, there's still a spot where the scratch was deepest (unfortunately in a quiet section) where there is a repeated small pop for a few revolutions, I'll probably be able to work this a bit more to improve further - but otherwise more than acceptable

If anyone wants to venture down this path and need any support or guidance, don't hesitate to PM me or ask in this thread.
Cheers
Dave