I got the same phone as you looking at your results.
On 3 web site they say Abingdon Oxfordshire is good to go for 4G so day I got new phone at local Tesco as an unlocked moto g 4G and fired up as disappointed it was back on the fast hspa + or whatever it normally is.
Found a rootmetrics web site and has peoples results at the places they are at. most of Abingdon 3g like always but a little bit near downtown showing as 4g.
Off I went to the best road for coverage on the map and noticed the mobile mast. missed that one and quite good at knowing where they are but not this.
Did 3 results walking maybe 200m in site and not of tower. Best I got on 3 was 50meg download.
If 2100Mhz or 800Mhz, who knows but me pleased.
Does just about work in the correct spot downtown.
These speedtests a bit away from shops in sight of mast.
Had 4G in Oxford. was a 7Meg down if I remember right.
on 3 I find the speeds ok on 3g, 4G not all it cracked up to be in Oxford.
http://www.speedtest.net/my-result/a/1139903629
http://www.speedtest.net/my-result/a/1139907834
http://www.speedtest.net/my-result/a/1139915638