The three middle value stamps went through prototype designs and there were other alternative values and sponsors considered during the design stages.

A sheet of test prints for a Farthing stamp in the style of the other three values and sponsored by the Wholesalers and Retailers of Fine Meats shows an alternative design and value for the Butchers and Tripe Merchants stamp. There were coloured and monochrome prints, and a series of three prints of different sizes to compare the details and the overall appearance of the printed result. The picture used is just a bit more than a sketch and would have been completely re-done if adopted. It does not look like an Alan Batley drawing, adding to the evidence that these stamps were largely a solo effort by Colin, though incorporating existing artwork by Alan.

There were at least three other designs, values and sponsors considered for the issue. These were a 2p Locksmiths and Bellhangers, a 6p Auctioneers and Valuers, and a 9p from The Brass Workers.

These are essentially the same as the issued designs with old illustrations and some experimentation on the text value box consistent within each value. The ideas progressed as far as sheets of colour trials sheets using gummed paper, although I believe these were printed by inkjet. Some mail emanating from Norfolk in 2007 was decorated with unperforated straight cut examples from a sheet, of these new values. There was a bewildering range of colours used on these stamps.

A selection of colours

I have recorded over 30 different value and colour combinations of these stamps, but it quite likely that a significant number of unrecorded examples exist; there are some very similar yet subtly different shades included in these colour trials. As yet no colour trials of the issued values have surfaced, but it is highly likely that those too existed in a comparable number of colour and value combinations, with colour options sheets printed. These sheets with a range of colours act as test beds for the issue, and quite possibly other future designs. You do need to ensure that the colours reproduce as you expect.
I believe that these designs were originally put forward as a design for the GCTS stamp - you'd trade in existing surplus stamps and receive a limited issue stamp in return. Hence they all have a hint of recycling about their subject matter.