The attached items might also assist:
The 1963 list shows that the main transmitters were all 100 kW erp, regardless of whether they were Band I or Band III, whereas the conventional wisdom was that to equalize signal strengths at the edge of a service area, around 300 kW erp was required at Band III against 100 kW erp at Band I (with higher powers than those of little value in extending the service area.)
Two-channel nationwide 625/50 coverage using only VHF channels was perhaps not so unusual. Here in NZ it was done using 9 VHF channels (3 Band I and 6 Band III.) When Band III was extended upwards to accommodate first one and then another extra channel, a third VHF network was shoehorned in, although I think with lesser coverage. To be fair, in NZ for a given high population coverage, the required geographic coverage was somewhat less, a situation that might not have obtained in many Northern hemisphere territories.
Cheers,