Oh dear, what have I started!
Firstly, thanks for your replies. Other than a few teeaks, I do indeed want to keep the build original, hence wanting to retain the chainstay protector.
This, however, means either polishing around it, removing and re-applying it, or getting another identical one.
Finding an identical replacement is proving difficult more than I had imagined. I am not fussed if I find NOS or have one made up, so on that note, can anyone point me in the direction of a new one in case I mess up my old? (No rubber alternatives please - Valentine's day or not!)