Go to www.BARefrigeration.com
I use them for work, they can make a custom gasket if needed. You can also call their support desk, give them the model# and serial# of the unit and they can get the right gasket for your application. They have the best prices that I have found with the best...
Below is the link to the article. I also PM'd you @fourfarthing
https://homebrewacademy.com/to-rosemary-or-not-to-rosemary-that-is-the-question-the-inspiration-to-brew-a-rosemary-ipa/