Auto repair shops used to have distributor-testing-machines and did in-house rebuilding.
Junkyards, Ebay, Auto-Swap-Meets, the Moparts Web Board, Year-One, etc, and (perhaps) Mopar-Performance or even regular auto-parts stores "may" sell the repair parts you need. You might just need to scrounge-around a bit to locate the parts or even an entire vintage distributor.
Same for a repair-shop or some place that you could send your distributor to for rebuilding/reconditioning. Maybe you can Google "Vintage Distributors?"
