All seems to be original on the pic.
I remember there is some sort of plastic fork crown on the steerer, part of the headset, i guess that allows things to stay in place even without stem.
Anyway if the wrong crown is on there will clearly be a gouge in it
if you take the bearing out, align a short ruler against the angled part of the bearing, look at it from above over a piece of white paper, you will be able to assess if its 36 or 45.
All seems to be original on the pic.
I remember there is some sort of plastic fork crown on the steerer, part of the headset, i guess that allows things to stay in place even without stem.
Anyway if the wrong crown is on there will clearly be a gouge in it