“Zinn was not a significant player. The card, and the brouhaha surrounding it, is more interesting than the man,” said John Thorn, the official historian for Major League Baseball. “If anything, it illustrates something so interesting about the hobby, the acquisitiveness about the fan. There is this transfer of power by owning this thing.”

McKee, a software engineer who now works part time, became a collector when he was 7 and ultimately concentrated on unique cards and sets. McKee periodically posts some of his cards on auction websites — mostly out of curiosity, he said. He tends to list his items at exorbitant prices because, he said, he loathes parting with any card.

“I got stuff up in my eBay store that is actually part of my collection,” McKee said in a telephone interview. “And every now and then, somebody hits the ‘buy it now’ button and I’ll scream.”

He did sell an 1894 Baltimore Orioles set — which was produced by the Alpha Photo Engraving Company — for six figures in 2006. McKee said the transaction had helped pay for his current home, but he declined to specify the sales price or the worth of his overall collection, which he called “too valuable to admit to.”

McKee displays much of his memorabilia in open cabinets and a World War II map case that he received from his Army National Guard unit. The more valuable items, however, are kept in safes.

“I keep a 9-millimeter in each one,” he said, then added dryly, “but I’d rather not use it if I don’t have to.”