Mine are really rusty - had been towed in the winter by the previous owners, and not washed down afterwards. Much, much worse than my 2005 Triton had been. I am thinking of replacing them, but I'm not sure how easy a job it is to tackle as a competent DIY-er (and once-upon-a-time vehicle mechanic). I'm assuming it's a standard shock absorber across the Al-Ko chassis models - mine has the blue plastic cap on, the same as ones I have seen on other WWBs with Al-Ko chassis.
After doing some research, it looks like "octagonal" blue ones for a 1300kg rated modern Troll. Possibly the appropriate weight one for an older Eriba too? The Al-Ko description and range is:
RANGE:
Single axle up to Weight:
up to 900 kg - green
up to 1,350 kg - blue
up to 2,000 kg - red
up to 4,000 kg- black
FEATURES:
Design up to 1350 kg single axle
Colour blue
Weight 1,3 kg
ean 4003718020915
Manufacturer Article No. 244085
Simon