The 60.5 ??ACME Thunderer....the large variety (tapered mouthpiece )
The 60.5 ??
Surely not ! The correct whistle is the 58 !
https://www.acmewhistles.co.uk/whistles-accessories/acme-classics/acme-thunderer
Don't think anyone mentioned the 60.5!
That's the tapered one isn't it ?