Tomato plant disease
Your plants are still looking pretty good and they should remain healthy enough for your tomatoes to ripen. This late in the season older leaves on the bottom of the plant will yellow. Pick them off and throw them away. Even if there is some septoria (a common fungal disease) there is no need to worry about treating your plants.
Thanks for your response. The local garden shop sold me some copper type spray to treat a possible fungus issue. With all the rain I'd probably exceed my credit limit to buy enough to properly treat those plants. Glad to hear it probably won't be necessary.
Go ahead and remove the leaves and see what happens. Good Luck!