I think the biggest problem with a Clyde Puffer is that it is too distinct. To my untrained eye, many of the alternatives posted look broadly the same. If one made a kit of any of these, you'd satisfy many anti-Puffers. Puffers look like Puffers, no matter how you cut it.
It's a shame many ocean-going ships are absolutely massive, even before Grouping. Makes modelling harbors accurately difficult.