This is bordering on being out of the scope of this BB but I will indulge you one more time.
If there is no ground present, you can either use a GFCI receptacle at the first outlet, use one at each outlet or use a GFCI breaker. You need to use the stickers "no ground present" on all of the receptacles.
On the other hand, if you determine that these boxes are actually grounded you could add a grounding pigtail to a regular grounded receptacle or you can use the spec grade "self grounding" receptacle that had a spring tab that grounds via the mounting screw. It was not uncommon in the 50s to use a grounded type of Romex and still install ungrounded receptacles. Technically the GI Bill required grounding the boxes but the farther you got from DC the less likely it would happen. I would test this ground with a Sure test or some other more capable tester than the simple three light deal.