Filson's Tin Cloth Packer hat is worth tacking down as is their Tin Bush hat
https://www.filson.com/men/accessories/hats-and-caps/packer-hats.html
https://www.filson.com/tin-cloth-bush-hat.html#
There are complaints about the longevity of the Packer, though
The Stetson waxed bucket hat has merit too .. some of it comic
https://www.stetson.com/store/catalogsearch/result/?q=bucket
That Filson Tin Cloth Bush Hat looks just the ticket if you could find one in the UK at the right size.