This is a NOS vacuum advance unit for the distributor for the years and makes listed below with distributor number IBP-4006 . This is a original NOS Mopar/Autolite part in it’s original packaging.
1889539 [Autolite P/n IBP2023LA 6-49]
Windsor; ALL with IBP4006 distributor
Saratoga; ALL with IBP4006 distributor