If the oil is coming out of the flange mounting it to the front cover, you should be ok with a new paper gasket. It is more likely that the oil is coming out of the weep hole about 1/2" out from the flange. If that is the case, your problem is the oil seal on the shaft. The pump has two back-to-back seals. The one towards the engine seals the engine oil and the one towards the impeller seals the seawater. There is a weep hole between the two seals to let you know when there is a seal failure. Mine started leaking and I hoped to do a rebuild but once disassembled I found that the shaft was too badly scored to rebuild so I needed a full replacement.