2.0 Cylinder head resurfacing

[Will 1967]

I'm having set of 2.0 heads (from 66') done by local machining shop. They are pretty good and have done fair bit of newer (2.2 and later) 911 heads but as 2.0 sealing surfaces are bit different, one thing should be clarified about resurfacing sealing surfaces;

I couldn't find from factory workshop manual other than: "Sealing surfaces of the cylinder heads should not be machined. Permitted distortion at the cylinder seating surface must not exceed 0.15mm (.0059") "

Surfaces are marked with red and green arrow in picture. So if e.g. sealing surface marked with green arrow is machined/fly cut 0.10mm to clean it, surface marked with red arrow should be machined exactly the same amount or is some tolerance allowed?

It might be that resurfacing is not even needed, and tbh, feeling bit stupid to ask this kind of question... Many thanks in advance!

(and pic is just stolen from internet and I added arrows)

[Flat6pac]

The red line is the insert of the cylinder into the head
The green area is the sealing surface with the head gasket
The head gaskets are upward of 1 mm thick and crush with torque.
Bruce

[Will 1967]

Thanks Bruce! So if minimal amount (like 0.1mm) is machined from actual sealing surface, is it necessary to make same roof for surface marked in red? (I used term sealing surface on there as well as I couldn't figure any other term )