I initially thought they were progressive but after closer inspection they are actually two-step linear. So deffo aftermarket.

2 step linear?

So not linear at all?

how does that work?

I run Hagon progressive springs in my road bike - they are spot on...

Sorry, probably me confusing things..

They are not progressively wound i.e. gradually getting tighter from one end to the other. IIRC this is how standard Honda springs are?

They are wound as per the middle one in the picture which is probably similar to your Hagon ones?

The standard nc30 springs would be classed as 2-step linear according to your pic.

Maybe they are std?

I need to do the fork seals on my bike and it "supposely" had Maxton springs fitted by a previous owner.

If I get round to the job at the weekend I will look out for any markings on the springs like you have found.
Hopefully, thanks to this thread, I can tell if they are linear or progressive too