I suggest that you pick up a copy of Lon Webster's Entrepot if interested in imported goods in the Confederacy. True, Tait did receive a large contract for uniform sets in 1863. Deliveries started to the ANV in December of 1864 if I am not mistaken. Major Tait's letters show that he was unimpressed with imported kersey already in the Confederacy when arranging the terms of their contract. This raises the possibility of substantial quantities of imported cloth in the ANV prior to the re-equipping of the ANV after Gettysburg. Ross and Collie also contracted for uniforms, some of the surviving "Tait" jackets may in fact be their products, but since there are no definable makers markings (excepting some P. Tait marked buttons) positive identification is, as of now, impossible.
Tait jackets (and English Imports as a whole) have several consistent features that make them distinguishable from all domestically produced Confederate uniforms. 1) the jacket is nearly entirely sewn with a lock stitch sewing machine 2) the shell jacket body is composed of 5 pieces, rather than the typical 6 (the center back is cut as one piece) 3) there is a double row of topstitching on the button side of the jacket front 4) all of the facings are left raw and the bottom edge of the jacket is rolled up and whipstitched to the lining 5) the collar is closed at the bottom with a brass hook and eye closure
Trim varies from jacket to jacket with several varieties known. 1) no epaulets and no trim 2) no epaulets with collar trim 3) trimmed epaulets and collar 4) piped epaulets and collar Apart from the trim variations, internal pockets come in two styles; a vertical internal breast pocket to the side of the left lapel and a horizontal pocket on the left breast. The horizontal pockets are only found on the piped examples, which incidentally are only known to come from the AoT and may be indicative of a particular manufacturer (perhaps Ross and Collie).
Alabama also contracted with Tait for uniform kits to be sewn together by Alabama seamstresses. These kits were delivered in the fall of 1864. A surviving example generally matches the "fully trimmed with epaulets" variety described above, but is constructed in the typical CS manner, with the lining and coat body sewn together show sides together, then turned right side out and top stitched. The coat was also originally constructed with a 5 button front, 4 more were added later to make a total of 9 buttons (Federal general service buttons if I call correctly) on the coat front.
Your coat shares none of these features and is best described as a RD II, although it is a fairly mainstream reproduction. As for the color of original RD jackets; although the imported kersey used for RD clothing is not the same shade as Tait, or other ready-made goods, it does have a blueish-gray color that is fairly similar. The charcoal gray color used by many sutlers (Richmond Gray) is, in my opinion, a reenactorism.
Cheers,
Garrett