How about when you put the cursor over the red dot on the radar it shows you an approximate altitude. Radar was sophisticated enough during the war to tell you what alt they were at, and I would rather not waste my time flying for ten minutes chasing a dot only to find that he is at 25K, and it is going to take another 45 minutes to catch him. I play this game to fight not chase people.
I don't want to start an argument, but I don't believe there were many radar sites capable of projecting altitude. They could most certainly see out to about, depending on the altitude of the object observed because radar is a "Line of sight" piece of equipment and the curve of the earth, limited them to about 200 miles if the aircraft was 18 to 25 thousand feet high.
The GCA, "Ground Controlled Approach" was a system which did have the capability of seeing altitude, as the operator could tell you if you were on "Glide Slope" or not. He could tell you if you 50 feet to high or 50 feet to low as you made your approach to the runway.
Even in the 50's, 60's and early 70's, the radar used by the FAA to handle all "Instrument Flight Rule" aircraft had flaws, such as a heavy rain shower would hide you from the radar, as it just showed a large green blob on the screen. Then in the late 70's, they developed radar which would "filter" out the rain showers. Even with that advanced system, the only way they knew your altitude was by "Transponder" response, or you told them after they asked!
I quit flying professionally in 1998 and even then, with in Terminal Control areas, (50 mile and in), I would be asked constantly my altitude as I was descending for an instrument approach to a large terminal area such as New York, Washington, Atlanta and I could name 20 more busy sites, the point being, they didn't have altitude information on radar systems then and I was less than 50 miles from the radar site.
I know the British were way ahead of us on Radar during WW2 so I don't know if they had that capability then or not. I know the U.S. airman where ask to report their altitude at certain "intersections", (point where 2 different radio signals crossed), so the controllers would know their height above sea level.
there is a ton of information on radar in general on line, but I would bet the military has the most effection radar anywhere and that is certainly not on line, at least not their greatest, latest magic boxes!