An assortment of one-of-a-kind Grateful Dead items auctioned off in April have been stolen from the auction house before they could be delivered to their new owners.

MySuburbanLife reports on the theft, which took place during the weekend of April 25-26 at Donley's Auction Services in Union, Ill. — and it sounds like it may have been the Dead equivalent of an Ocean's Eleven-style heist.

"The items were being processed for shipping, and a number of them were awaiting pickup by armored car," notes the report. "Only local events were scheduled on the complex and the thieves had to get past staff employees to reach the prep area."

The stolen items are said to be worth roughly $75,000, and include some prize collectibles for Dead fans, including an original 1966 poster by artists Stanley Mouse and Alton Kelley that Mouse recently hand-painted specifically for the auction. "After 49 years in storage, Stanley decided the anniversary year would be a good time to hand-embellish his original silkscreen. Because it was painted only last fall, the colors are far sharper and more vibrant than the original," noted auction house owner Randy Donley. "This is not a piece that can be resold. It is too well-known."

The thieves also absconded with a pair of Dead tour posters from 1986 and a 1966 print, hand-signed by artist Wes Wilson, that marks the band's first use of a skeleton. Local police are investigating leads in the theft; meanwhile, Donley is offering a reward for the items' safe return. "Please help us solve this crime," he asked readers, imploring whoever has any of the prints, "Please do not destroy it for fear of getting caught. We just want it returned."

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