Stephen Nelson is a College of Business instructor. Fewer Butler University students probably know he is also a toy train collector.

Nelson opened Mr. Muffin’s Trains, a toy train collection with an operating layout, in December.

His interest in toy trains began when he was 14 and started working at Ed Schock’s Toy & Hobby in Broad Ripple. He worked there through his time at Broad Ripple High School in the early 1970s.

“Before Toys ‘R’ Us and Walmart, it was the place to buy your little brother a birthday present,” he said.

Nelson is a businessman and full-time instructor in Butler’s College of Business, but he said he sees his hobby as the antithesis of business because he has no interest in making money from it.

While Nelson said he has been interested in model trains for a long time, he shares a unique experience on his website, www.mrmuffinstrains.com.

Nelson underwent surgery for colon cancer in 2005. While under anesthesia, “I found myself floating down into the seat of an old Madison passenger car,” he said.

What Nelson calls a “Messenger” then told him the train was meant to make him comfortable on his trip to heaven.

Nelson awoke in the hospital and later discovered that during surgery he had technically died after a cough dislodged his ventilator.

Nelson has been collecting these particular trains since 2000.

“We have a very large collection, one of the largest in the country,” he said.

Mr. Muffin’s Trains is located in Carmel just feet from where the Monon Railroad used to run.

This is an appropriate location. The Monon Railroad, which ran from Lake Michigan to the Ohio River, was a hugely influential railway.

According to the history page of www.monon.org, the railroad carried soldiers south during the Civil War, carried the body of President Abraham Lincoln after he was assassinated and carried limestone from Indiana used for the construction of the Washington Monument, the Empire State Building and the Pentagon.

There is no admission fee to the shop, and the storefront sees about 50 visitors per week.

The name Mr. Muffin’s Trains comes from one of Nelson’s old nicknames, he said.

“I designed the logo in about 2000, when I also started to sell things I had collected on eBay,” he said.

The whole model train track in the store’s layout is finished, but only about 10 percent of the trains are on display. The staff is also about halfway done with the scenery and hope to finish it within the year.

Nelson and his crew spent ample time on the scenery, he said, making it look very realistic.

Mr. Muffin’s Trains is the biggest toy train layout in the state and is set in the 1950s. Nothing is modern, and the trains are mostly post-war passenger trains with 1950s-model cars.

The layout does not model any particular town but is meant to be very urban.

“There are city scenes,” Nelson said. “There’s a bad neighborhood with bars, a coal mine, a dog food factory and a Twinkies factory.

“There are also animals, people, an automobile accident and a skunk in a trashcan, which I always try to get younger children to find.”

There is an open stairwell in Mr. Muffin’s Trains, which Nelson said kids love to climb to get a bird’s-eye view of the layout.

“It’s really exciting to introduce this hobby to young people. We also have a lot of senior citizens that come from nursing homes that had trains as kids.”

Nelson, through Mr. Muffins Trains, plans to continue expanding his layout and sharing his passion for trains with children and adults alike.