Just added to the site: T 18374B Rebuilt 12-volt Clock Assembly for your 1956 Thunderbird (Plus $150 Core). Also available: 6-Volt for 1955 (T 18374A) and 12-volt for 1957 (T 18374C).

http://www.larrystbird.com/product/t-18374b-clock-assembly-rebuilt-12-volt-plus-150-core-fee-1956-thunderbird-t18374b/

http://www.larrystbird.com/product/t-18374a-clock-assembly-rebuilt-6-volt-plus-150-core-fee-1955-thunderbird-t18374a/

http://www.larrystbird.com/product/t-18374c-clock-assembly-rebuilt-12-volt-plus-150-core-fee-1957-thunderbird-t18374c/