Allisport fabricate intercoolers. I don't think they're that pricey.
But – WTF would oil be coming out of an intercooler? Intercooler normally refers to an Air / Air heat exchanger – ie, a radiator full of pressurised air from the turbo, cooled by ambient air in the engine bay. There should not be significant amounts of oil in it.
On the other hand, a Chargecooler is an Air/Water heat exchanger, you have pressurised air from the turbo being cooled by the same coolant that runs through your rad. Obviously, that could concievably leak, but it wouldn't be leaking oil.
You'd also notice a fair performance difference, and possibly fault lights due to excessive intake temperature with either of these items being leaky.