New guy needs help with an old steam whistle

Hello all, I’m new here because I had an old steam whistle land in my shop, friend of mine wants to see if I can restore it. He said it came from his father’s locomotive when they retired the engine, he kept the whistle. I have reason to believe it’s a Nathan type 963, as I have been given a drawing of what appears to be this whistle. Anyway, I’d like some advise on restoring this and any information someone can give me about it. I’ll try to post some pictures up but I am molding technologically deficient at times. Thanks for the help!