hi m8 i had the same prob with my97 turbo wagon.
We took our car to greer sport and they fixed everything the list included the two rear gudgeon pin seals and a few seals in the oil pump, the two front gudgeon pin seals and also the crankshaft oil seal. This stopped our leak and they resealed the sump just to be on the safe side!!! If you want their number pm me and ill pm you their number. Top quality service and no oil leak now after all that work.
Wullie
ps the both rocker cover gaskets was changed and the spark plug hole seals.
pmsl (rocket gasket)