Sky Blue coffin vases are on pg.36 of the 1980 catalogue.

But, yes, I've seen some of the other work of the Horncastle chap, and it's such a shame that he's decided to take this route - but I suppose if you're an independent glassblower in a market constantly calling for the cheapest glass rather than the most well-made or original glass then it can be hard to ignore the call of this avenue where you're guaranteed very regular sales.
And it should be noted that whilst morally and/or artistically dubious, it's not illegal as he's producing copyright-lapsed designs in non-WF colours and is not trying to pass them off as originals. What others subsequently do with his output is where the legal grey area lies.
And also, it should be emphatically noted, Whitefriars themselves produced a lot of copied glass in the 'Glasses With Histories' series.