Readers;
The coat style is of the Mexican War Era. So a pattern would be easy to find. The gauntlet cuff is a style from circa 1750, and so also easy to find a pattern.
Another solution would be to buy the Workmans Coat Pattern(see my earlier thread on this,) add the band collar and gauntlet cuffs, since it is a doublet. The cuff detail on the left hand image is the sort on a P.C. coat, hence it would be, 'one degree of less formal' than the gauntlet on a Doublet.
In the proposed image, the double breasted coat is a circa 18th Century military style. The two lapels are sewn on the fronts, just for show. That coat would need a vest(weskit)to go with it. With the Workmans Coat, the fronts can be buttoned open or closed, which would give you some options of wearing different items with it.
It is a good idea; it could be made up in black wool, or even white linnen for summer wear. Amoung other fashion ideas we have lost(see the thread on black/coloured leathers)in our era, is the concept of a white summer formal wear attire. Sink me!if I would never wearablack wool doublet on a hot Flordia fancy dress ball!
But let us know how it progress.
AS Ever
CSA