I have a pewter that has a perpetual nose whistle. I've had him for about a year and he has retained the slight whistle despite having multiple full sheds.
As long as you don't see any other RI indications, it won't likely be a problem. Perhaps it is some stuck shed in the nostril, perhaps that is just how his nose is!
Same here, I have two snakes with a soft whistle but no other symptoms and otherwise healthy. I keep saying they just have 'talented boogers'.... :p
Kimbly
Pastel 'Cami' Mojave 'Tank'
Kingpin 'Cleo' KillerBee 'Buzz'
Pied 'Patches' Lesser 'Lieutenant Dan'
Mojave 'Lyla' Het Pied 'Norm'
2 Normals 'Audrey' and 'Girl' Fire 'Smokey'
Black Pastel '#3' Normal 'Slim Shady'
Butter
Sassy and Reilly, our furry girls