I'm no ATSF expert, but the -52, -67, -71 were built by
General American. The -75 was built by ATSF. (From kits?)
The -65 was built by ACF. RMJ 8/1991 has photos of one.

The Ga-71 roof had seam caps, so that is a noticeable
difference from any kits (Kato/Bowser/Intermountain). I
think Sunshine produced a minikit with a replacement
roof to model this car.
Tim O'Connor

From the Society's Live List and folio diagrams where I have them,

the GA-52 and 67 were from ACF, while the 65 and 71 were from GAT.



The folio diagram for the GA-75 shows two series.

182060-182309 had radial steel roofs reclaimed from BX-8,9 & 10

box cars.



182310-182559 had Murphy solid riveted roofs.



As you say Tim it lists the builder as ATSF.

No info as to who the supplier may have been if they were kits.

Cheers

Dave North