The sign is a subtle joke. The shop is called "Sneed's Feed & Seed", where "feed" and "seed" both end in the sound "-eed", thus rhyming with the name of the owner, Sneed. The sign says that the shop was "Formerly Chuck's", implying that the two words beginning with "F" and "S" would have ended with "-uck", rhyming with "Chuck". So, when Chuck owned the shop, it would have been called "Chuck's Feeduck and Seeduck".
🍷 Ah yes, I can feel my head throbbing with knowledge and wisdom as I sip upon this Sauvignon blanc. Come chatroom, who will join me in this endeavor of knowledge