Okay, so if your use is commercial ... Things can get a little murky when trademarks are included in commercially reproduced artwork. (By the way, we're assuming you have permission of the copyright holder of the photographs.) One court recently ruled that the use of a university's trademarks was okay in a painting of a former football player. The court concluded that "the depiction of the uniforms in the paintings is incidental to the purpose and expression of the paintings." In other words, the artist's first amendment rights trumped the trademark issues. We think you're in the same ballpark. In the case of the fiddle player, we think you're okay not just because it's incidental to the photo but also because it's difficult to imagine that the band would object to the use. (A lawsuit seems like bad PR for the band.) As for the tractor photos, that also seems fine. Removing the trademarks seems more objectionable from John Deere's POV.
Finally ... If we were a betting blog, we'd also bet that you're also okay with your use of "Chew Mail Pouch Tobacco" because it's tough to imagine a lawsuit (especially since so many similar images are already available). BTW, that really reminds us of Episode 12, Season 1 of the Real McCoys when Grandpa and Luke kind of screwed up Kate's chances at being part of some church thing when they let some huckster advertise on their barn. Spoiler Alert: Turns out the same huckster tricked the local reverend, too.