After reading lots of good info here I wanted new struts my old ones were shot.
They are now finished and fitted and work a treat, if I push the rear hatch button the deck lid lifts then a gentle nudge send it slowly skywards until the struts are extended, and it stays there.
I bought 2 new struts the same length as my original ones, with the proviso that the ends must be removable, also the pressure within (Gained here on the forum) was 400newtons.
I removed the old rods from My original struts, had the tubes powder coated and new decals made up. Then the new struts were fitted inside the original strut tubes with a spacer at the bottom so the new strut sat in the spacer and was held centrally, The original top strut connectors were fitted to the new strut ends (using a helical) to keep them looking original.
The struts were £72 and engineering costs £20
decals free from my son in law and Powder coating £5.
they look well too see pics Hope this helps someone.