c&m hemstock antique chicken brick/cooker

I recentley picked up an item in a storage locker it's a antique chicken brick with markings on it it says chicken on top than below it it says c&m hemstock and old great north road sutton on trent and it's made in england i can't find any info on this or value the only thing i have found was that there is a similar one in  amuseum called burton art gallery and museum i wanted to get this appraised b/c my grandmother is not doing well at all and i was selling and trying to get appraisals on my items to see what they are worth to help her out if anyone can give me an idea or any info on how much it's worth me and my granny would appreciate it thank you so much

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