Yes, I think that is probably correct.
I know of a test version printed on 1 Feb '44, marked as Nr. 1.
Another test version marked as Nr. 7 was printed on 29 Feb '44.
At a meeting on 2nd March, Delmer reports that the Nachrichten project was viable and that the proposal for a daily air-dropped newspaper should be put formerly to SHAEF. It is also noted that the cooperation of the U.S. Special Leaflet Squadron would be essential.
So presumably at some point between the 1st March and 24th April, one more test issue was printed.
Delmer had not supervised the earlier tests and was not entirely happy with them. He did not like the choice of photographs used.
Also it is interesting to note that the masterhead of the test versions was different to that used on the production newspapers.