If interested, I can post here pictures of maker marks I have found, not on Heers, but on 2nd Lufts (basically the same blade with different fittings).

I have found the following Zeitler maker marks:

1 line mark across the blade
1 line mark along the blade
1 line mark along the blade no dash (probably a very light strike of the above)
2 line mark along the blade rounded
2 line mark along the blade stamped

John

TM 2.JPG (36.13 KB, 446 downloads)
TM.JPG (37.53 KB, 442 downloads)
TM 1.JPG (36.5 KB, 440 downloads)
TM Rounded.JPG (37.69 KB, 441 downloads)
TM 2 Line Stamped.JPG (39.91 KB, 442 downloads)

Always looking for Eickhorns and etched bayonets.