We are having trouble with the seal between the transmission and the rest of the drive unit after having it serviced. The oil leaked out between the transmission box and the fibreglass part of the drive unit. The machine shop had used a paper gasket and some sort of red sealant. We are on anchor so are trying to do it ourselves. We took it apart and resealed it , it leaked again after about 4 hrs motoring. We had used a high Temperature RTV gasket maker but no paper gasket because we thought that that was the way it was originally. We have the plans from Amel, but it is not clear if there should be a paper gasket. Should we try to find card to cut a gasket or try again with the RTV gasket maker? The fibreglass part is not in a very good condition.