Question regarding the RCA 630TS cabinet.

[benman94]

There are two variants of 630TS cabinetry with regard to the mounting of the safety glass. One variant uses four small clips in each corner of the safety glass. The other variant uses one large clip centered on top, and then two small clips in the bottom corners.

Which variant is earliest?

The earliest advertisements (December of 1946) I can find show the four clip variant, as does the factory service information. Chuck Azzalina's site says that the four clip variant is later than the three clip.

Any ideas?