Lincolnshire Police are appealing for information after a theft in North Somercotes, near Louth.
Police say the incident happened on February 11.
According to Lincolnshire Police, a bicycle was taken from outside McColls, in Keeling Street.
The bicycle has since been recovered, but multiple train set items that were stored in a bag on the back of the bicycle have not been recovered.
A Lincolnshire Police spokesman said: “We are asking who has seen these items, or knows anything about the incident to call in on 101.
“These items are of sentimental value to the owner, and we are encouraging whoever has them to please hand them in.”