Several Welshs hat have the motto Honi Soit Qui Mal y Pense (May he be shamed who thinks badly of it – the motto of the Order of the Garter) on the label, mostly without the name of the maker.
Two of these was made by Carver Jefferis and Comp.
This is very similar to the crown, coat of arms and cartouche on labels for hats made by Carver and Co, late Dale and Co of Bristol
The Prince of Wales feather might signify that this was made in Wales; but most other hat labels include the Royal Coat of Arms, so this might mean that a Prince of Wales purchased items from the firm.
A hat with Diew et Mon Droit also has the Prince of Wales Feathers within the cartouche.