This is a first - sold unseen! But then, breeches are so difficult to find.
The images you see are good references of the type of breeches for sale.
Image 1 is taken from 'Nineteenth Century Costume' Laver, 1947 [Victoria & Albert Museum] and is Figure 9 on page 5. Here we can clearly see the fall front on the gentleman's breeches, which are tucked inside his boots. I love the comment by Laver: 'The country gentleman's riding costume has now established itself as normal informal wear in town'. The year of the Plate - 1807.
Image 2 is from another of my favourite books: 'Old English Costumes', undated and published by the Victoria & Albert Museum in conjunction with Harrods Ltd, who held an exhibition of the most famous costume collection of Talbot Hughes. Note how, in those days, actual models were allowed to wear these historic costumes!
Here we see a rather more formal gent on page 46, Plate 32 entitled 'A Beau of the Early 19th Century'. Again, we can see the fall front of the breeches, the narrow legs, and the side button fastens to the leg 'cuffs'. These are rather long, and unfortunately the publication is rather vague with dating the outfit, but a glorious image of the gent in full dress. 
My breeches are most like the first image, and as they came to me with a date of circa 1810, are probably the closest in date.
Gentlemen's breeches are so very difficult to purchase. I have examined a few of the 18th Century, but never Regency, so I am delighted to have studied these. It is lovely to also think the gent may have ridden in them, as well as gone for a country stroll with a young lady on his arm.
The breeches are black, and made of facecloth, which is a very fine wool. Remember that this fabric never frays at cut edges, so there was no need for edge seams. Given their age, this facecloth is remarkably fresh in appearance and although there are small issues, I would think these breeches were not worn very often. The black colour is true black, with no fading at all.
So, we know who the owner of the breeches was because he wrote his name of 'Wolley' inside the waist band, onto the cream canvas type lining. 
This fabric is also used to provide a hidden inner pocket, quite small and narrow, perhaps to keep coins/tokens.
On the other hand, the fall front, front facings and leg 'cuffs' are all lined in a gleaming glazed cotton, which supports all the buttons and button holes to prevent wear.
The breeches are rather small, so perhaps Mr Wolley was a young man, but given the smaller size of everyone in this era, we cannot know for sure.
The shape of the breeches is very close fit and with narrow legs, that possibly go to the calves in leg length [see later measeurements]. The rear of them is not baggy, as one often finds in 18th Century breeches. He would have little room to move!
Buttons! Oh my! So many of them! There are different types for separate uses; but I feel quite sure they are all original to the garment, the thick linen thread a delightful confirmation.
First we have hidden buttons to fasten centre front, then there are those to fasten the fall front. Buttons also to attach braces, at back and front. I'm not sure what they all do, but a gentleman will know. 
At the leg fastens there are four cloth covered buttons to each legand then at the base, a narrow strap. At first I thought this was for a buckle but studying the images above, I am not sure that a buckle would be used when tucked into riding boots. Again, for further research. There is no evidence of button loss. 
I have to tell you that the hand stitching throughout is simply wonderful, so beautifully made throughout, and a joy to study. 
The measurements are as follows: Waist 28", Waist band 1.75" deep, Side length including cuffs/ bands is 31.75", Inside leg 19", Lower leg cuff 12" and Upper leg width 22".
Although the breeches appear very fresh, there are some minor issues. Please read the condition report below. Any dust or fluff comes from my struggles to put the breeches on my modern [ladies] legs! The breeches are not dusty at all.