The suspects have attended the location and gained entry to the outbuilding by removing rear wooden panels.
The offenders arrived and left the location in an unknown vehicle, which was driven across two fields.
A Lincolnshire Police spokesman said: “We believe this theft was carried out between 10pm on Thursday January 2, and 10am on Friday January 3.
“We are asking for members of the public to contact us if they saw any suspicious vehicles or people in the area within these times, or have any information regarding the stolen items.”
You can contact Lincolnshire Police:
• By calling 101 and quoting the incident number 112 of January 3.
• By emailing [email protected] - remember to put the reference 112 of January 3 in the subject box.
• Call the independent charity Crimestoppers anonymously on 0800 555 111