You're making more progress than me.
I started checking coils and the aerial coupling coil (L1 on Trader Sheet 236) was open circuit. The can came off easily and the lead outs were seen to be burnt - not that clear in the image below:
An extremely knowledgeable member of this forum has given me guidance to rewind the coil but I'll check all Coil Unit 2, Coil Unit 3 and both IFTs first. If I find any more this fine set may be sold for spares.
