Comparing the roads shown on the map drawn in captivity from memory by Capt. E Jones of the 2nd Glosters (taken from his diary) with modern maps the D11 leads out of Cassel towards the west, with a double-bend to negotiate a steep hill, leading to Calais and Gravelines. Shortly after the double-bend the D52 splits off to the right going north to Dunkirk, indicated as L'ANGE on this map. Another map in Capt. Jones' diary shows L'ANGE is where the D11 to Gravelines crosses the D338 from Wemaers Cappel to Haeghedoorne, this latter road being 'Route de l'Ange' on modern maps.
One thing on that map that does not tie-in with today is the reference to 'Villers Capel and Calais' heading left. This has to be an error and should be Wemaers Cappel (on the D11 modern maps), shown as 'Weimirs Cappel' on this drawing by Col. E. M. B. Gilmore of 2nd Glosters.
That aside, it puts the 'Villers Capel and Calais' road on Capt. Jones' map as A on the modern map, the branch to the right ('Lange') at B, the St Omer road at C, and the 'Dunkirk Cassel' road at D. The farmhouse occupied by 10 Platoon of 2nd Glosters will be at E. Immediately south and left of that, on the sharp left-hand bend, is shown an A/T gun at H, and a litle further along the road from that a road-block before the fork in the road. Given that Harry makes reference to the road, a road-block, a ridge, and a farm that had been occupied by 2nd Glosters where he bagged his fourth tank, I'm pretty sure that the A/T gun position on Capt. Jones' map - 'H' on the modern map - is where Harry was. Google Maps show it as a good defensive position on a ridge (centre of picture, shown up well by the low sun), with clear views across the plain for miles. It's true that the farm occupied by 10 Platoon would have been to Harry's right and not the left as he says, as would Dunkirk ("seen burning in the rear"), but the only other A/T positions marked are much closer in to the town, on the St Omer road, with buildings of Cassel behind them blocking the view towards the coast.