Vintage DuPont Advertising: NO PLACE FOR A FROG: Osthaus, Dogs, Winchester Gun?

Description

Hi there! I ended the previous listing and relisted it so that I could add more photos, eBay would not allow a revision because of the sent offers or watchers. I noticed a spot that needed to be explicitly mentioned, up in the top left corner. It looks as if there is wear to the image OR there is something in between the image and the glass. Please make sure you view the enlargements, and I am marking this beautiful, beautiful piece down because of it.
ORIGINAL LISTING:
The previous owner said that this was extra special because not only was it DuPont advertising, but that the frame was a Winchester advertising piece. I do find other instances of this 'No Place for a Frog' image being attributed to Dupont, mainly when it was reprinted on a calendar in 1910, but can't find anything about the frame.
I am not sure, but think it may be a lithograph print on linen? Hopefully you will be able to tell by enlargements.
Frame measures approx. 17 2/8 x 13, image inside is approx 13 x 7.
Postage includes insurance.