A nice sentiment, but Not the same whistle! 90s rebuild in Tuam was drastic a Complete nut and bolt rebuild lot a loco already tired at the end of service, and left outdoors for 25 years! The whistle currently on 90 is said to have originated from the GWR.
Within 90 there are parts from 99, 100, sprite, an E class and bullied Beet Wagon!