[cbenham]

There are pictures of RCA color prototype sets and converters in the RCA 'Redbook' which is RCA's Petition to the FCC to adapt the NTSC color system.

One set that your description made me think of is a #2 Converter. This was a 'table-top' looking set that was designed to be used with an existing B&W set.

The converter had all the color circuitry but made use of signals from the B&W set's RF and IF circuits. It would have been the 15 inch CRT. The description says it was used in demonstrations in 1950-51. The description also says there were several cabinet style versions of this converter. Perhaps you were looking at one of the others based on the look of the 241 set? See Attached... Cliff