Two things perhaps to consider:
1. The use of Fraktur fonts in *
new* KTBs seems to have ceased around mid/end 1941 (after Bormann's January edict). It was replaced with Antiqua fonts.
2. From early 1942 the format apparently became more of a standard essay. The bottom example in the link that BBW posted -
http://www.uboatarchive.net/BDUKTBFormat.htm - shows the new style.
One KTB I have dating from 1943 (perhaps the essay style wasn't overly popular with anyone other than Doenitz, LOL!) shows the headings as:
* Datum und Uhrzeit
* Angabe des Ortes, Wind, Wetter, Seegang, Beleuchtung, Sichtigheit [sp?] der Luft, Mondschein USW
* Vorkommnisse
Essentially the same as the image above.
Another, which I think is newer, simply shows the headings as:
* Tag Uhrzeit
* Ort Wetter
* Vorkommnisse
With a vertical running "Heftrand" written in the, surprise surprise, margin.
Both use an Antiqua family font.
I remember researching all this when I first built the KTB feature into SH3Cmdr - it uses a compromise between history and SH3.