The map commonly printed in various accounts is the map created by Jason Gurney. A copy is attached below. Gurney's account of the battle itself is well worth a read. His book was published after his death. He is at times critical of the battalion and some of the decisions on the day. After Jarama he was attached to the American Battalion.
By having his account published after his death he may have wished to avoid confrontation.
His map covers a fairly large area. He and a colleague only had a couple of hours or so to prepare the map. His map contains various errors but that is to be expected.
Without his map the British Battalion would have gone in to battle with very little knowledge of the ground over which they were to advance.
The map above is the version freely published in various accounts. One of the key factors is the inclusion of the positions of the battalion as they moved forward and finally engaged the enemy. These movements were later additions to the map. They were not added by Gurney at the time of his survey. In fact they could have been added well after the battle itself bearing in mind the battalion only spent three days in or around the sunken road and Suicide Hill.
On the morning the map was produced it was being used in discussion between Wintringham and Brigade Command west of the sunken road before the British Battalion appeared. At that time the positions were obviously not marked on the map.
That being the case the battalion positions should not be used as a reference point in order to extrapolate the map over any satellite overlay.
Gurney refers to the plateau, the sunken road and the escarpment whilst he undertook his survey. That being the case it is to be expected that the key points he maps close to his physical position will be more accurate than those further afield. He did not advance further forward than a short distance from the Sunken Road due to probable enemy presence, the unknown and limited time.
Standing in the same area the landscape appears relatively flat. In otherwords it was more of a sketch that an artist would produce under the conditions.
The furthest west of his map shows the Jarama River. The actual positoin is about 1 mile further west. This indicates the further away he was from a mapped point the greater the error.
As the final forward battalion positions are not accurately positioned on the map that does not suggest the rest of the map is incorrect in its layout. In fact the area east of the 680 contour is an excellent reproduction of the British section of the battlefield
Consequently the following points are surprisingly accurate. They are all more or less east of the 680 contour namely the area in which he had free access.
-Cookhouse and hill west
-Chinchon, Arganda and morata road
This can be seen in the overlay overleaf.