Simanco needle bar 2050 has no timing marks

Dears,

i am currently working on a 1921 15k (Scotish) and trying to set the timing. Now here is the issue. The original needle bar (p.nr.: 2050) does not have visible timing marks. I checked also a lot of images of (original) spare parts and none of these (2050) seem to have marks.

Can anyone help me out here? Am i missing them (i cleaned it really sorrowly)?

Grateful for any hints or tips in the right direction.