[Mondial]

There is also another error on the 118 schematic. If you look closely, the screen grids of the 78 RF and 78 IF tubes are connected together with no source of B+. In the actual set, the screens of the 78's and the 6A7 are all connected together and obtain B+ from the voltage divider resistors 67 and 68, which are bypassed by the 2 uF electrolytic 46. It appears there is a dot missing on the schematic where the two perpendicular lines cross.

Yes, it seems that the 42 can operate with very good triode characteristics. Looking at the data sheet, a pair in push pull can deliver up to 13 watts with only 2% distortion. Compare that to a single pentode 42 output which only puts out about 3 watts with 8% distortion.