Yes, Major, You are absolutely correct: The cuffs, collar and tails would need to be changed if one was using a military coat pattern to make a civilian coat. My suggestion was in reference to the *cut* of the coat. The way the back fits; the way the front fits the body; the way the sleeves fit into the coat: These things can be taken from a military coat pattern.
By referencing some of the book patterns (suggested above) one can get a good idea of what the collar and tails should look like and how they should fit into the pattern pieces you already have for modification purposes.
Blending, for example, one of Past Patterns military coats with the images of the civilian coat pattern pieces will allow you to start with a commercial pattern that will give you a beginning for fit, sleeve shape, etc.
The technique I use to blend a commercial pattern is pretty “rough and ready”... I trace the pattern size I think will fit the person. I trace onto tissue paper (I use the rolls of examining table paper that can be purchased at medical supply pharmacies. It’s inexpensive and sturdy enough to use for sewing patterns.) Then I “eye” the shape of the book pattern pieces and just freehand sketch on the additions or the changes as I wish. Taping paper together to make big enough pieces is generally involved.
When I think I’ve “guessed” right, I cut this modified pattern out of inexpensive muslin fabric. I sew up using red thread and the largest stitch my machine does so that ripping out is easy and seams are well marked. The next step is trying on this muslin mock-up.
I use a red pen and I start drawing directly on the mock-up (this is why I prefer plain muslin to inexpensive patterned fabric. I want to clearly be able to see my notes and redrawn lines. I might make an exception for a windowpane check that would also give 1 inch or ½ inch increments.) I make notes about the fit directly onto the muslin fabric. I pin where necessary. I might even take scissors to the mock-up to change the shape of something.
By the way, it makes this fitting process easier if the mock-up is made with 1 inch seam allowances. I draw that one inch seam allowance (in red) on the fabric before sewing up. When trying on, seam allowances are generally put to the outside for easy access and manipulation. Things like collars may have seam allowances to the inside so size and proportion is easily assessed.
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If you decide to seek out a tailor of historical garments, I’m afraid I am ill-equipped to help you with tailors on the U.S. side of the border. I have worked with Stan Boyle at “History in the Making” and his work is superb. I did work with him at a distance. It was a museum job and there were several men involved. I took the measurements Mr. Boyle requested.
www.historyinthemaking.org/catalogue/Catalogue_index.html This is a detail I would recommend: If your military tailor is not making civilian clothing and if you are dealing with another tailor at a distance for your civilian coat, ask your local tailor if he will allow you to pay him to take the measurements for the civilian tailor. You need the measurements to be taken by someone who understands how to take measurements. (I know it sounds simple and silly – but it’s amazing how often measurements for distance work can go wrong when a non-sewer is measuring.)
If you decide to work with Stan Boyle, clarify, specifically, the years you are looking for in a coat and ask to see pictures of a similar coat. Stan works with many, many eras and the work I had him do was not for 1812. In other words, decide if the coat he’s offering is c.1810 or 1825. Obviously, you don’t want the 1825 coat.
Another source for inquiry for you might be to ask about tailors here:
www.militaryheritage.com/film1.htm I know Mr. Twist a little and his understanding of men’s wear for the 1812 period is second to none. I know the tailor working for him, but I hesitate to share that without suggesting you go through Mr. Twist. Primarily they deal in military clothing, but they may also be able to help you with civilian clothing and may be able to recommend a tailor on the American side of the border.
I hope all of that will help. I know it’s a lot of information and babble.