Um i'd replace the chassis if it's got expanding foam in it anywhere else, it's pretty much fooked, the foam is porous and will hold water and rust nicely from the inside out.
it's the only place where there is expanding foam someone must of tried a quick fix at some stageall the holes i could find in chassis are on pics could have been alot worse as it was parked on a harbour for 12 months:doh: thanks for advice