Early or late stub axle

[Heaver]

Looking to change the front stub axle, as the threads on the centre shaft have gone, but little confused after reading a few forum posts on early and lates.
My vans from 1981 but I think I have a late stub axle, as there’s no threads in calliper mounting holes?!? Is this normal?

I have ATE Brakes.

[Aidan]

'early' is fixed calliper fitted with M14 bolts to the upright/steering knuckle
'late' is sliding calliper with carrier fitted with M16 bolts M16x1.5mmx48mm
check the bolt size but it does sound like you have the later uprights and brakes fitted