Luckily I have found the original report on Gomog (see below). It was not Lookheed Martin which I recalled but Freightliner in Portland, Oregon who did the exploration on a Morgan car in 1995. Very interesting that they could prove that the size of the (then used) radiator was totally ok and the issue has to be resolved by changing the airflow, not the radiator itself.
I only noticed that the even bigger size of my in other respects brilliant aluminium radiator emphasizes the issue of the airflow when blocking its effectivity at higher speeds and when the temparature rises accordingly.
Here is the article which is the initiator of my idea to repeat their procedere to mount a flat floor underneath the gap between radiator and engine which will become an early spring project for me.
