T206 Leach with attached card on back

[brianp-beme]

Just another fun and interesting card in my collection. This T206 Leach Bending Over card has a section of another card attached that was used to either reinforce a very heavy crease or to bring two separate parts together.

My inquiry is this - what card back is it? Of course I know that the actual card is a Sweet Caporal 350...even I could figure that out. I originally thought the back stiffener/reattacher was a T206 Old Mill because of the parallel black lines seen, but upon comparing it recently, I think the line spacing is off. Is it indeed a T206 Old Mill, or perhaps another T206 back? It also could be from another set, or even perhaps a non-sports card...does anybody recognize it?

I also like the fact that a previous owner updated his uniform to reflect that in 1912 Leach became a Cub.

Brian