FWIW I think the guy on eBay is misinformed and/or optimistic. That said, you could always list for $2K and see what happens - LOL - original frames are worth something and listing is free right now. The two that sold for $550 are not original frames and were cut to fit the frames they are in - or so it appears to me.
I think the eBay provenance is off. J Hoover's store was not on Market Street in the 1870's. The earliest I find (from my poor memory of yesterday) is Chestnut St and he was there through the 1890's. It was located on Market Street in 1934/5 and maybe before that. I can look it up if you like on my genealogy subscriptions. Whoever wrote that on the back of the eBay chromo may have purchased it from Hoovers store (??) on Market St but they didn't buy it there in the 1870's. Also, J Hoover & Son's weren't typically doing this style of chromo portraits - or at least I didn't find an example. Middleton focused on the subject. In the few portraits that Hoover produced, there was always some other scene in the background (I don't have the right words).
You will also note the writing is not very "period" to the 1870's like yours is.
I will probably never be able to prove it but I have a sneaking suspicion it was EC's son, Edward that was distributing these prints maybe with his father's help. EC left the biz by 1870 when he sold his second company and listed himself as a Real Estate Agent in a Census. However, his son Edward stayed close to printers throughout his life. Edward's FIL was a Tinner, BIL was a painter, and Edward was a pattern maker... Later in life Edward became a traveling salesman and was living in MD. He is listed as a boarder and his landlord was a Printer. Edward died in DC in 1908. I'm still working on him... LOL
Also, I found an unmarked Lincoln and am guessing I’ll find more unmarked examples eventually.
