Jim and Alan, thank you very much. Alan, if 947177 has a bluing issue, then so too does 947176. Might you have a picture of an example of a purple tinted HSc frame you would share? I'd be pleased to take/post "revealing" pictures of this pair if I know what to look for/capture in the image. I'd merely compare these with another late war blued example if I had one, but I've only got phosphate.