I had intended to use a Chime whistle for Papyrus and found , at least a similar whistle as the one I had seen in a video about the whistles of Flying Scotsman, on Ebay. It was a 6 tone Chime whistle and so I changed it to a 3 tone one.
But it was in vain, because meanwhile I had found out that no Chime whistles at all were fitted to A1s/A3s, except to 4472 when it visited the US in 1969.
Rgds
Bernd