This series of short string whippings would look more 'sympathetic' ... even "folky". On a wooden whistle (well, if I had made ... anyway) I might turn the oversize diameter to create a series of ridged separators ... not much relevance to cheap whistles.
I first played evil old (1960s) Generations that did not have good mouthpieces. Once they worked out how to make a plastic mouthpiece, there was little further problem (pace Leadfingers - not too many whistle players even know that there are any third octave note available ... and a good ear - good quick adjustment - and a quick touch to any third octave note all help!).
Clarkes have been very sloppy from the factory, post Clarke family ... but are amenable to extensive 'tweaking' - starting with making the wind channel they shape it should be. Sweetones are a fair compromise if you baulk at a bit of tin manipulation. (Chiff & Fipple whistle web site reckon they are the most popular cheap whistle in the world).
Susatos can work well (pace SarahtF) and give good hard working tone in a large group or session. The narrow bore "A" is a bit tight for many, but I've lived with a wide range of bore characteristics. My "A" actually cracked in the slidng part of the head joint (probably due to an over-enthusiatic adjustment, late one night!) - but a definitely non-decorative 'whipping' holds it nicely together ever since.
Mark Cohen: If you thing L.E. McCullogh's book was a bit less than user-friendly ... you should try listening to his playing examples on the accompanying tape ... It nearly made me take up glockenspiel!