Class numbers in the 70s? 

Was 7* under TOPS reserved for electro-diesels or for DC diesels?

Empirically, the Woodhead locos (76 & 77) do indeed suggest that the 7* series vs. the 8* series was for indeed for DC locos (catenary or 3rd rail). However I've never seen it claimed that this was particularly deliberate, whilst I have read that the electro-diesels were deliberately grouped in this range. Does anyone have a robust source?  

In the meantime I've reverted the change, mostly to avoid the redlink. If we do change this, the link ought to point to a section within the TOPS article.