lock ring thread advice requested

A few weeks ago I took a rear wheel (fixed) into a bike shop near work for truing.
And they were all like "yeah mate £15 mate come back monday"
Monday rolls around... I get a call:
"Sorry, we couldn't save it. We have a new wheel for you. We will sell you it for £50.00 and also for another £10.00 we will transfer your freewheel over and install it to the new wheel".
"err.. OK. Can you transfer the cog/lockring too please."

So that was all right, if expensive perhaps. (was happy enough to pay for immediate service as I was getting fed up of riding geared). Somehow I didn't think to ask for my old (buckled) wheel, was only a cheap one but could have yielded hub/track nuts spares and so on. Would have been nice to have been offered it back in any case.

Anyway, after a period of riding a silly ratio, today I finally went to put a larger cog on. Took the lockring off and was slightly nonplussed by the looks of the thread.


Was unsure if it would be OK to try and put the lockring back on there, or if i should be taking it back to the shop, so I rode home from work on the freewheel which proved a mite tiresome, esp. uphill, lower ratio notwithstanding.

I know the pictures aren't the best, but if anyone can make it out from the above I'd be grateful for advice - does it look like the thread is damaged?..
Or is it perhaps just minor debris on there; e.g. bits of the (Surly) lockring or something? Tried to pick a bit with a fingernail, it moved a little but did seem quite attached (didn't want to pick at it too much)