I have noticed the spackling appears to be dry underneath, but at the opening of plane where the motor sits, or another way the belly of the plane where the cowl would attach too, the spacklings seams to be drawing some of the oil/fuel. Origianlly the covering was attached to this area. In an earlier  posting someone had mention to rub cornstarch on it. So I thought maybe I would go buy some corn starch and pile the starch in that area.