He said thieves had broken down the fence at his Adwick-le-Street home and taken the trailer from the drive.
The incident was reported to South Yorkshire Police on Sunday, he said.
The group of 20 re-enactors perform as figures from the 12th and 13th Centuries at sites such as Pontefract Castle, Sherwood Forest, Leeds Tattoo Festival and Nottingham Castle.
“We can’t do the displays. We can’t do any cooking, we can’t house ourselves at this point in time,” said Preston.
“All of this equipment has been bought over years and years. The group’s been going since the late 1990s.
“I’ve been re-enacting for nearly 45 years and it’s the accumulation of all those years’ worth of work, not just me but for the group.”