Just an update for this: There are certain acknowledged classic texts on puntgunning, the building, equipping and use. Some of these are now very old, rare and very expensive. However this situation took a surprizing recent turn.
First Lessons in the Art of Wildfowling by Abel Chapman. 1896 First edition. Available online from Abe Books from £95 to £267. There have apparently been no subsequent reprints until...
2017 facsimile softcover/hardcover from India. £9.18 to £10.91. I now have one of these. Quality is quite good except that the fold-out drawings of the original are shown unfolded in the facsimile. For the price, understandable.
The Wildfowler in Scotland by John Guille Millais, (Guille is a baptismal name for the family which lived for centuries on Jersey. It is pronounced like the first syllable in Guillotine. Millais like Mill-lay). He was known as Johnny.
The 1st edition, 1901, goes from £45 to £400 pounds Stirling. 1974 is the first Tideline Books edition. £21 to £60. 2005 is the second edition. £20 to £28.
The Complete Waterfowler ashore & afloat by Stanley Duncan. 1911 & 1912 editions. £68 to £232. Revised 1950. £42 to £81.
The result of this is that, thanks to a 1974 reprint by Tideline, a 2017 facsimile from India and a well-priced 1950 revised issue by Duncan, I now have all 3 without a second mortgage.