I've checked the magazine. At this time there was a monthly article under the heading of "Wer? Wann? Was?" (= Who? When? What?) inside the Fliegerrevue. The questioner asked for the HJT-17, but in the absence of detailed information the answer only contains a two-page description of the HJT-16. The wooden mock-up of the HJT-17 had also side-by-side seats - this is the only information available from the magazine .
Btw, V. M. Ghatage was the head of the development team for both designs.