Featured Pigot & Co Map of England & Wales 1825 - help please

I don't know if this is the right forum on which to post this, but I hope that there are some map collectors or experts here. I have come across a map which I acquired so long ago that I can't remember anything about it, it probably dates back to when I used to go to collectors' fairs many years ago. It printed in sections as far as I can make out, and pasted onto linen, which has spent much of its life folded. The edges of the sections have come away at the folds and are curling, leading to some loss, but the linen is holding up well (although very grubby now). It was printed by Pigot & Co, with a date on the bottom of 1825. It shows England and Wales, and shows the main mail roads, turnpikes and canals, but not railroads, which were not built at that time. There is a Pigot map online which calls itself "Pigot & Co's New Map of England and Wales . . ", which I think implies this is the earlier one, but I can't find any copies of this map anywhere online, for sale or reference, no mention at all. The most common map of England by Pigot is 1840, the 1830 one is very scarce.
Can anyone point me to a resource to research this map? I'm hoping to put this on sale, but only if it's rarity makes up for the condition. I hope someone will think it worth the time and care needed for restoration.
The size is about 51cms x 66.4cms.

 

I can't help with the map, but this is a good forum for it.

 

I found this from Christie's. It is for two Pigot's titles bound into one cover. Seems to indicate that the map was a folding map published in Pigot's Commercial Directory of London. But that directory doesn't have a date listed. It is bound with a directory of Scotland from 1825-1826. https://www.christies.com/en/lot/lot-4917723

I am traveling and currently using a very old computer that will not show me the images from Christie's. Don't know if they will help. Based on this, the theory is that the map you have was a folding map bound into a directory, and that it fell apart from repeated folding and unfolding through the years, and that somebody removed it from the directory and mounted it on a linen backing.

 

That's it, thank you so much! There don't seem to be any images online, but folded into four the map fits the description of the volume as quarto. The explanation fits perfectly, and explains why there seems to be a little loss of paper along the internal edges of the pieces even though they were pasted closely together. They must have become ragged in use. Did you notice that the estimate was a nice £300 - £500 for the volume containing the map plus other maps and a directory, but the whole lot only made £84! That was back in 2007, but I think I am forewarned that my map will have to start at a very low price indeed if it is to sell at all. I just hope that someone will take on the challenge of repairing it and enjoying a snapshot of the time just before the railroads and industrial revolution changed the map of England.

 

Oops, I've just seen that the volume at Christie's was described as octavo, which seems to cover various sizes but is smaller than quarto. Nevertheless, I think the idea that it was originally folded into a volume holds good, because it explains the narrow missing area in the middle, and perhaps also why there don't seem to be many on the market. The maps that remain are possibly still part of other volumes, so difficult to find with a search. How did you find it, by the way?

 

old European measures for book printers.
https://en.wikipedia.org/wiki/Book_size
only useful when the sheets used were of the same size; a quarto is double the size of an octavo, but only when the original sheets were of the same size.
today's general rules of size go back to the Prussian regulations (Preussische Instruktionen, 1880s)) that introduced a given size of sheet 33*42 centimeters. most probably to stop the English and US nonsense of inventing a size for every printing machine of every machine company.
today's list for normal use:
1 Plano plain meaning the whole sheet
1/4 Quarto quarto
1/8 Octavo octavo