This distributor body - which appears to match yours - is an "Autolite" variety. Ford used as OEM on the years up to '64.
The bowl above the stem is deep enough for a centrifugal advance mechanism - and as mentioned above, if you lift the cap there are no springs to be seen on that type of distributor.
I have found "Old Stock" freshly
rebuilt "Autolite" point distributors (by Vapex and others) - but they are few and far between.
Also as mentioned above, the "tri-lobe" stem was used on the "Motorcraft" distributors produced after '64 (used on a large variety of Ford engines) - and those housings are always found to be re-cycled/re-used on the Cardone re-manufactured Y-block parts. I don't believe the tri-lobes were ever used on a factory built "Y" engine - only the Autolite.
Steve Metzger Tucson, Arizona