The band plan would imply that it is an ECI cabinet since the band plan U2 and D3 end at 2770 and 4083 likewise.
From a quick skim, I can see that you've got interleaving enabled on your line to deal with errors (and it's doing a good job as most of the errors are corrected as noticed in the FECs). Though this can take a small chunk out of your sync speed if memory serves me.
You not being able to sync at the full 80 any more is mostly because of crosstalk. It is not entirely unusual to lose 20+ Mbps from crosstalk (sometimes a lot more when referring to the attainable rate), especially on a cabinet that has a high amount of subscribers.
I could graph your data but it's a bit late at the moment. Plus, seeing as you have the ability to graph from DSLstats then I won't bother. Though personally I would recommend graphing the current stats with HG612 modem stats (
https://kitz.co.uk/routers/hg612stats.htm) if you have a compatible device because it is less fiddling.
The attainable figure is what the modem believes is possible with current conditions. The modem can sometimes be a bit overzealous with the attainable. It may show a much higher figure than what you sync at because of the presence of interleaving (I am not sure, but I think that this is the case).
Anyway, I am going to take a wild guess that you are about 500 meters away from your cabinet.