Is this the same handle as the 39' popular?
No, the knurling pattern on the Populars were slightly different. This one is identical to the OC Aristocrat's just on the thinner handle.
The 38' Sheraton has the un-notched center bar
None of the pre-WWII razors had notched center bars. That didn't happen till 1948.
The change in the Sheraton head that I'm talking about above was it going from this:
to this: