CLAYTON -- Most days, a visitor can find Sam Robertson in his office at B.M. Robertson Mule Co.

Sipping a cup of coffee, the 90-year-old is surrounded by photos of his family, model airplanes and medals from his time in the Air Force. Robertson, who lives just one block from his office, is quiet about his military service, but he is eager to talk about the five sleighs, five buggies and three wagons parked inside his building.

Each piece, dating back at least 75 years, has its own story to tell. Robertson’s favorite is the buggy he found under a shed in 1975. He had planned to trade tractors with a Pine Level farmer but made a pitch instead for the buggy, which has leather seats.

“I asked [the farmer] if he wanted to sell it, and he said it belonged to his wife,” Robertson said. “I said, ‘Did she want to sell it?’ He said, ‘I don’t know. Let me find out.’”

Not far from the buggy is a wagon that Robertson’s nephew, B.M. Robertson II, received for Christmas in 1941. Today, Sam Robertson and his nephew own B.M. Robertson Mule Co., one of the oldest businesses in Clayton. Robertson keeps the office clean while letting his nephew care for the precious cargo.

“Most of the equipment was on the shelf, but he took it all down,” Robertson said of his nephew’s efforts to organize the goods. “He did a good job. He did it all. I don’t take any credit for that.”

Before antiques started taking up space, B.M. Robertson Co. sold farm equipment and mules. Sam Robertson’s late father, Battle Moore “Bat” Robertson, started the business with four other partners in 1902. Eventually, he bought out the partners and added “Mule” to the company name. Bat Robertson and friend Sam Musgrave also owned Tennessee Mule Co. near O’Neil and First streets.

The building on North Lombard Street could hold as many as 50 mules. Back then, mules cost $250 to $350 each. Under a skylight in the building’s center, the owners showed mules to prospective buyers.

Many of the mules came to Clayton by train from Georgia, Virginia, Missouri and Tennessee, Sam Robertson said. “One time I went with [my dad] to St. Louis, and we were probably gone a week or 10 days,” he said. “He must have taken me out of school when I was 5 or 6 years old. That was just out of this world. For a little fella, it was a particularly long trip.”

Robertson and his brother, John B. Robertson, ran the business after their father’s death in 1929. Gradually, mules gave way to tractors. As Robertson traveled to Pennsylvania and New York to buy used farm machinery, he often stumbled upon buggies, wagons and road carts.

Robertson was not one to refuse a good deal. “When I would go north, a lot of time, if I had an empty spot on the truck and I could buy that sleigh or buggy cheap enough, I did,” he said.

About six years ago, Robertson decided to stop selling farm equipment. But he could not let go of the building that bore his father’s name and legacy. Now, he will share his prized possessions with the public for a second year. The Clayton Historical Association will open B.M. Robertson Mule Co. for tours during Millstock on Saturday.

But don’t expect Robertson to be there. These days, he prefers quiet over crowds. “I used to have a whole lot of friends come here and drink coffee with me,” he said. “But it’s just me drinking the coffee now.”