Thanks for all your comments my friends. I won't be doing the anealing thing but will just gently clean them up before re-using them once. It sort of spoiled my day when I got the circlips

and not the washers in the post today

but like all the times before, I've been given some very sound opinions and advice and feel comfortable I can re-use them tomorrow.
What would I do without this site, I don't know
