I had a number of left over Perry plastic confederates in hats and waist-length jackets. I also had the slouch hat and head metal conversion pack that Perry makes so you can change up hats. The Perry confederates all having the short jackets gave me an idea for giving them an alternate use.
For my modest, small Union army in 28mm I wanted to have at least one "typical" looking Western theater Union Army regiment, maybe from the Army of the Cumberland, Army of the Ohio, etc.
So, from my years of reading and studying, I remembered a reference I came across of some Union soldiers that had been issued frock coats who cut off the skirts, and converted them into improvised shell jackets of a sort. The skirt cloth was then saved for general clothing repair patches, gun cleaning patches, etc.
This made the coat somewhat cooler as it removed the cloth that would be hanging around the hips and upper legs.
The regiment that was referenced was a western regiment I believe, but the exact regiment escapes me now.
However, there was some suggestion that the practice may have been more prevalent than some realize, perhaps in both the western and eastern theaters. Of course, it was probably also forbidden in certain commands to modify the coats in this way. And of course many commands would start campaigns in the fatigue blouse and ignore the frock coat altogether. So there's a whole host of potential scenarios. If my memory serves correctly, Union soldiers as a general thing were often given the choice of taking the fatigue blouse or the frock coat as their primary garment when a campaign opened.
Another historical reference I used was the common practice of cutting down the issue Hardee hats and making them a "one story affair" instead of the taller height they were issued at. Another common practice was to crease and reshape the crown of the Hardee hat to the soldier's liking.
The resulting general look is what we imagine when we think of the western federal armies, as a general thing.
So here I'm loosely representing a Wisconsin regiment in standard federal issue gear, with the cut down issue hats, possibly some of them with the modified frock coats, or issue shell jackets. One of the flag bearers is the lone Perry Union plastic figure in the regiment, he has a fatigue blouse, and is indeed the only figure in the regiment with a fatigue blouse.
But bear in mind, my regiment is simply representing a very wide cross-section of what a "typical" western federal regiment may have looked like based on what we know about what was issued and what soldiers did with the clothing they got.
I had this Troiani painting in mind when making up the regiment: