Good catch. The data plate says mfg. by Autocar so it should be a AC/DT/White style. If you read the text regarding the M3A2; the rebuilds were performed by IHC on several Autocar M3s (t29) and several IHC halftracks(t31). One of the other photos in the series shows a t29 dash and it seems to be the AC/DT/WT style. Since the IHC dash was actually more like an M-series plug and play dash I bet that was where the ordnance dept wanted to go and since IHC was doing the work to both types (t29&t31) it seems likely they would have made this upgrade.