PITTSBURGH — One could think that 65-year-old Jerry Weber, the owner of Jerry’s Records, sold his soul to the devil given the kind of luck he’s been having scrounging up impossible-to-find records lately.

In November, Weber and his 34-year-old son, “Whistlin’ Willie,” got their hands on a 78 rpm copy of Mississippi bluesman Robert Johnson’s “I Believe I’ll Dust My Broom” (Vocalion), one of the most important blues songs of the 20th century.

For days after a stranger dropped off a box of moldy 78s, they sat among boxes of dispossessed but possibly interesting vinyl at the store. When the Webers finally got around to conducting an inventory of the box, they found a clean copy of the Johnson classic.

After picking themselves up from the floor, they realized they were in possession of one of the few relatively unscathed copies of the record in existence.

Fast-forward to a few weeks ago.

This time, the younger Weber spotted a strange record by Bogus Ben Covington, a performer he’d never heard of, among some Blind Lemon Jefferson sides they’d recently bought. Because of their good fortune with the Johnson find months earlier, Willie had been paying more attention to every record that crossed his desk.

“I’ve developed some expertise in 78s,” Willie said. “When I get records, I listen to them all.”

The A-side of Covington’s 1928 record was “Adam and Eve and the Garden.” The B-side had the even more evocative title “I Heard the Voice of the Pork Chop.”

Like the Johnson 78, it was in impossibly good condition. In fact, it had never been played as far as Willie could tell. It also was on the rare Paramount label, making it one of the most collectable records in the world, sight unseen.

After consulting Dixon and Godrich’s “Blues and Gospel Records 1902-1942,” Jerry and Willie contacted Penn State music historian and record collector Jerry Zolten.

“Paramount didn’t use the best shellac mix,” Zolten said, explaining the recording’s fragility and rarity. “Jerry and Willie managed to find a copy that looked like it just came out of the store.”

Zolten then made a suggestion to the Webers: The reclusive underground cartoonist Robert Crumb, who last visited Jerry’s Records in 2004, probably would jump at the opportunity to own a rare Bogus Ben Covington record.

Crumb, 69, is a fanatical collector of country blues 78s recorded before 1935. According to Zolten, who has been friends with the cartoonist since 1980, Crumb has a particular interest in rare Paramount sides. Zolten put Willie in touch with the notoriously shy artist who now resides in the south of France.

After an exchange of emails, the Webers and Crumb agreed to a trade: Upon receiving the Bogus Ben Covington 78, Crumb, who is acutely aware of the value of his art, would send a pen-and-ink drawing of “Juice Jar Jerry” and “Whistlin’ Willie” to the states suitable for reproduction on T-shirts and posters.

The Webers, who now own the rights to the drawing, are free to do anything they want with it.

“A lot of people assume that it is no big deal for Robert to knock off a drawing,” Zolten said. “He will put hours into a drawing. It is impossible for him to do a quick drawing. Robert doesn’t do a lot of trade for artwork like he used to. He’s well aware that his work is fetching large amounts of money. He tries to parse these things out. Robert said it was the best known copy of the record, so it was worth it. He likes the idea of owning it.”