Hi FarmerFiona;
Welcome to the forum.
It's hard to believe the Smart Smoker has be out for over four years. The Digital Generator LED 120V NTC is specific to their digital line of smoker, so this would not be compatible with the Smart Smoker.
You may want to give Bradley a call. You will get a message, leave a message, but at the end of their message they will give you and email address. Follow-up with an email, you will probably get a faster reply.
Canada: 1-855-772-3539
United States: 1-866-508-7514