A first look at data show that:

injected lines at 6.7 Hz and above are all well visible in hrec (using 1000s spectral resolution)

Yet, the choice of setting lines's frequency at multiples of 0.1 was not good, because of the presence (forgotten) of an underline 0.1Hz spaced comb which is largely coherent between hrec and magnetometers. Therefore, we would possibly repeat the injection with a better choice of frequencies. 

Injected lines below 6.7 Hz are not seen in hrec (although there is margin of improving, for example removing loud glitches...). These freqeuncies should be amplified. Indeed there is margin (before saturating the amplifier) to safely double their amplitude.