I can't even recall coming across Clare Whistles as a brand. It's hard to remember exactly what was in the shops decades ago when I bought some of my whistles, but I'm pretty sure I haven't seen any for sale recently, at least from British suppliers.
To go back to OEMs, alibaba.com has plenty of Irish whistles. A typical listing:
https://www.alibaba.com/product-detail/ ... 407aqW19wN
This firm specialises in making musical instruments, but another company offering what appears to be the same whistle apparently has 5 - 10 employees and its main products are baby strollers, kids toys, trampolines, artificial lawns, and kazoos.
One has sacked old Tom in Quality Control:
https://www.alibaba.com/product-detail/ ... 407aqW19wN
This is a version of the whistle that's different to what is on sale in Ireland. It appears to have thicker walls and the matte finish looks like an aluminium alloy of some kind (scroll down for close-up photos):
[
Edit - sorry, posted wrong link and I now can't find the one I meant!]
It's possible not all the companies offering whistles via alibaba.com actually make them, they could be part of a chain of resellers, distributors, and other middle-people. The range of unit prices might hint at this.
Finally, this is the luxury version, but it can still be had for $8.50 US:
https://www.alibaba.com/product-detail/ ... 407aqW19wN