5372A update:
Needs new battery. Other than that, as advertised. To a maths half-wit like me, it does take some time to get into the device to actually comprehend it, but I've gotten a lot of insights already. My FeelTech FG has a pretty bad oscillator, that's the first thing I've learnt. If I plot the frequency from it as a graph, it flips between two frequencies, one slightly above, one slightly below 10MHz. The average is some 45kHz off.
I perhaps should buy one of those 10-packs of CTI OXCO too. The 8316 counter needs one too. And, as soon as I get to borrow the GPS-steered Rb reference from work, I'll get to characterising the OXCO in my Meinberg LANTime, which is displaying tendencies to deviate too.