possibly I'm confusing things .............. there may be some C19 W/Fs factory drawings in the 'big book', but what I'd meant by my comments - about drawings - referred only to the Stuart factory drawings that relate directly to their Registered Designs in 1906, 1908 and later ones up to and beyond the 1920, that were submitted to the Board of Trade - the drawings that are located at Kew.
I could be very wrong, but have a feeling that W/Fs didn't submit any drawing to the Board of Trade - meaning that there aren't any W/Fs Registered Designs at all.
I have pix for virtually all Reg. Designs from c. 1840 to end of the C19, but never got around to snapping those after that date - and post 1900 for sure is where you will find the Stuart pix at Kew referring to your conical bottle.
My Reader's Ticket expired some two or three years back, so will need to renew - will of course let you know as and when I find the post 1900 Stuart pix covering this leather bottle design.
As we know, some designs are copied many years down the line - using either original moulds or not as the case may be. The attached is an example of a Stuart design for a handled claret jug which I found in recent weeks, locally. It's marked with Reg. No. 681269 - one of three Nos. allocated to Stuart on 21st February 1921 - a period when they were very active with the Board of Trade. It carries a matching No. 8, which for the body is in fact near the top of the handle.
But there's no way this piece was made in 1921 - far too unmarked, too clear and clean by far - it has just the word Stuart on the base (though I suppose it might have been in Granny's cabinet for one hundred years)

Some Stuart Reg. Designs are known to have been produced continually for 60 - 70 years - designs such as Woodchester and Strafford Rings.
Let's hope that given time we can nail the details for this Stuart leather bottle. Makes you wonder though, had W/Fs Registered this particular pattern if that might have prevented Stuart from using the same design.