[SURTEESS]

Ewie, thanks for the info, at this stage I do not think the gaskets are the issue.
There appears to be a vertical crack showing where the light is located, in the USA made version it is made of 2 layers - the vertical crack is in the inner layer, I think it is caused by heat stress cracking from 5W bulb, hence there must be a small gap between them, that is where the moisture droplets occur.

Do not feel like breaking apart the whole assembly at this stage, will wait till someone else has done it (on a damaged unit) - just a thought has anyone fitted different lens/LED to one of these marker units (got photos).

Will try & get a couple of smaller wattage bulbs for the future, at this stage I will try to "bake-out" the moisture & reseal with clear RTV around the edges.

Will check with Winger here in Auckland if the outer rubber seals are available & if so - how to fit them.