They're from the John Deere Supreme Plus-50 0W-40 CH-4/SL synthetic that's currently in my car. It's a Chevron product.
The bottles actually contain different oils, thus the duct tape. I had some partial jugs of Valvoline Maxlife 5-20 and Mobil 1 0W-30 that I measured out and poured into the quart bottles for easier top-offs or whatever I come up with as a use for them. While measuring those jugs out, I discovered just how incredibly inaccurate the markings on the side of 5 quart jugs are.