I am sorry Alan that you find it surprising I did not give GTH a mention but I am not well read, do not have the time, and did not know of his table.
I cannot say that my offering is totally from my own head but prompted by a photograph I had seen during my time as editor, I now find is was acctually in issue 1 of MEW. And the person who made that was a Tony Daish and I did not give him a mention either.
It is probable that GHT had also been influenced by others offerings.
I have now found the GHT table in the Hemmingway catalogue and can see some long distance similarities. Though I do not see fine adjustments of the stops, 24 hole indexing and, for me, the inbuilt facility to be able to centre workpieces very easy.
It is quite probable that over the years I have produced items that had a noticeable similarity with items designed by others, its inevitable. I can assure you that this is quite coincidental. For me, designing an item is much more satisfying than the making. If I just largely copied others designs most of the satisfaction would be lost.
If eventually Alan you decided to make one please feel free to make contact with me via my web site should you have any questions regarding the areas that you do not find clear. I will do my best to help.
Harold