A Postal History Project Help Request - Chatfield & Woods

I recently joined the APS and started looking through their online exhibits. That is where I found an exhibit that told the story behind certain covers: https://stamps.org/events/virtual-s.../exhibits#22
This inspired me to try to make my own, so I chose this cover and got to work. Below is a quick overview of what I learned, but you can skip to the end for the point of this post.

I was not expecting to find a lot of info, but what I found surprised me.
Through my research, I found that Nixon & Chatfield originally began as Nixon & Co. It was run by Thomas Nixon and his brother, Martin Nixon, and it came about in the 1840's.

Ad from Robinson & Jones' Cincinnati Directory, 1846.

Thomas and Martin Nixon were born into the paper manufacturing industry, as the Nixon family was one of the largest manufacturers of paper in Philadelphia at the time. Thomas moved to Ohio to begin a new business and Martin partnered with him, but remained in Philadelphia.
Their Cincinnati paper company would undergo many changes in the coming years. Edmund O Goodman, one of their Cincinnati competitors, would partner with them in 1856 to create Nixon & Goodman.

Ad from William's Cincinnati Directory, 1857.

Goodman would depart from the firm in 1858/59, and the firm would become Nixon & Chatfield.
William H. Chatfield worked as the cashier at Nixon & Goodman and would become a partner of the business in 1859.

Ad from The Cincinnatus, 1860.

William Woods would join the company in 1861, resulting in the Nixon, Chatfield, & Woods company.
Martin Nixon would depart the company between 1860 and 1865, focusing on running the Nixon Mills in Philadelphia.
Thomas Nixon would depart the company in 1865 and move to Dayton, Ohio, where he would start another paper company.

After the Nixon's departure, the firm was renamed Chatfield & Woods.

Chatfield & Woods expanded from paper manufacturing to flour sack / bag manufacturing, twine manufacturing, and roofing materials. They would also open a second factory in Pittsburg, PA. Chatfield & Woods existed until at least the 1960's, the only record of which seems to be calendars they manufactured.


So I'm asking everyone here if they have any covers or documents related to:
E. O. Goodman Co.
E. O. Goodman & Co
Nixon & Co
Nixon & Goodman
Nixon & Chatfield
Chatfield & Woods
From Cincinnati or Pittsburg

I have found a good amount of online resources in the form of directories and newspaper advertisements, but not much else.

Here's a cover I saw in ebay sold listings, before I began my little project.

Ain't Postal History great!!!