Thanks for that, Malte. The readings yielded (my voltmeter is off by +0.02 so 0.03 should be read as 0.01):
16':
0.03 | 0.05 | 0.10 | 0.19 | 0.37 | 0.73
8' highest C (all others are like the previous one starting from the 2nd reading):
| 1.47
4' highest C:
| 2.96
Bob mentioned to me that I may have an issue with the positive part of the antilog circuit.
Cheers,
Yash