So the Army situation was that after Dunkirk the 59th (Staffordshire) Infantry Division arrived in the area sometime in June 1940. They were here until October 1941 (moved to Northern Ireland)
Replaced by 15th (Scottish) Infantry Division, which remained here until September 1943.
Now the invasion panic I assume started after the retreat from Dunkirk, so the majority of the WW2 construction around here would be done by these divisions. I assume in the hot seat to get the job done would be the Royal Engineer Field Companies of the two divisions, with working parties from the Infantry.
So probably the information on these WW2 'constructions' lies in the war diaries of these engineer units. There were three, (perhaps four in the case of the 15th?) in each division:
59th (Staffordshire) Infantry Division: (6.40 - 10.41)
509 Field Company (11.1.40 - 22.8.44)
NA
510 Field Company ( 2.3.40 - 22.8.44)
NA
257 Field Company (23.6.40 - 22.8.44)
NA
15th (Scottish) Infantry Division (10.41 - 9.43)
278 Field Company ( 3.9.39 - 31.8.45)
NA NA ('round Alnwick' - our most likely candidate for Amble constructions?)
279 Field Company ( 3.9.39 - 9.2.40 and 12.7.40 - 31.8.45)
NA NA ('round Wooler')
280 Field Company ( 3.9.39 - 15.12.42)
NA NA (location not given)
20 Field Company (26.3.43 - 31.8.45) NA ??
I've added some national archives links for my own reference, they are not complete (will have a better look later). Would be a big job going through that lot.