I got this distributor with my recent '32 Chevy project. No idea what it's for. I know it has a crazy small drive gear! I accidentally broke the cap. It's complete otherwise. Has the numbers "555" cast into the housing.
By golly, I think your correct... look at the similarities in the vacuum pod. So, v8-60 size? https://www.hotrod.com/news/simca-ford-flathead-v-8s-until-1961-found/photos