Unless they were to do something completely incorrect for WWII airborne radar, none of the WWII radar sets would be useful in AH.
Hmm, going by memory here, so I might sound like a fool..but..

Didn't the ground radar/radar operators had much more effective radar with larger "field of view" on the screen? This data would be transfered to the pilots, which had their planes with their own small radar, and when they got close enough to the bomber formations, they would be able to see it on their "small' radar.
If this is the case (though something tells me it's not), then perhaps in AH, planes with their own radar system could have an constantly updated radar status around them, say 10.0K. So if you were to open up your clipboard, and there happens to be an enemy within 10K, you would see their movement (without delay), on the clipboard.