Is the Necky Spike linear or cross-linked poly?

Anyone know if the Necky Spike is linear or cross-linked poly?

Suggestions on best way to fill/repair screw/bolt/rivet holes?

If it says made in Canada it should be the good stuff…
Now I have to remember which is the good stuff…
I think it was cross-lined…
I had an old Necky Dorado that is still around the hood and is in great shape…