Tried the JB Weld method of repair but to no avail, just resulted in a slightly less ferocious jacuzzi when re-tested.
Anyhoo, after a bit of deliberation i decided to go down the route of replacement cores and use the OEM end tanks.
I went with Pro Alloy as i liked the cut of their jib and the cores turned up today

I got them slightly wider than standard while i was at it and i am hoping to get them welded into the end tanks tomorrow and fitted in the next few days.
Should be an end to the infernal intercooler problem for a lot less than a new set of OEM's
Will post up a few more pics as the job progresses but here's a couple to start off with:-