[Arran]

It should perform better then a pair of straight triodes as the suppressor grid will eliminate the secondary emission problem. I'm not surprised about the error on the 118 schematic, it doesn't make much sense have a screen grid connected in that manner, sort of just sitting there with no B+ on it. I guess the purpose of the .006 uf cap is for tone correction, since it isn't present on the 660. I have a Canadian Philco 3118B, and finally got a replacement speaker for it, so I have a little more motivation to get it going. Like most 18s and 118s the 6500 ohm bleeder resistor has failed, I think it needs a 20 watter as a replacement, but I only have a 10.
Regards
Arran