Rare 'Inverted Jenny' stamp owned by metro Detroit attorney hitting the auction block

(FOX 2) - One of the most sought-after collectibles in the world is about to hit the auction block.

An iconic 1918 Inverted Jenny postage stamp has been in the hands of metro Detroit attorney Ronald Bassey for more than 40 years.

It's called the Inverted Jenny because of the upside-down JN-4 airplane depicted on it. Only 100 were printed before the error was corrected, and only 94 are known to have survived.

The stamp's face value in 1918 was 24 cents. 

"That was a big number," Bassey says. The Robert A. Siegel Auction Galleries website says the cost was so high - a first-class mail stamp at the time was only 3 cents - because the United States Post Office was experimenting with carrying mail by air. 

The story goes, one lucky man heard of the mistakenly-printed stamp and came across the whole sheet at the post office an was able to make the purchase. Bassey says that man then sold the sheet to someone for thousands of dollars, and the collector item kept growing from there. 

Eventually, the stamps got separated.

Bassey owns the stamp that was in position 11 and paid $36,000 for it in 1977.

"I figured it could only go up and it seemed to increase in value during downturns," Bassey says. He says only he and his wife have known since then that he owns the stamp. 

"Everything I've gathered is that this is the most famous stamp in the world," Bassey said. "It's not the most valuable in the world, but anything that sells for a couple hundred thousand dollars or more catches people." 

Bassey says the highest price an Inverted Jenny has ever gone for was more than $1.5 million. Bassey says that stamp was perfectly centered, while his stamp is slightly askew. 

He's thinking his stamp could fetch at least $200,000 during the auction on July 1. 

Bassey has other stamps in his collection as well and says he's been collecting them since he was just 6 years old.