before you go changing the seal, check if oil is dripping from the dipstick tube mate, i once found oil and was going to change the seal as thats what it looked like, but after a good inspection it turned out to be the o-ring of the dipstick tube was not up for the job anymore and was leaking a bit.. oil was going all the way down just after the crankshaft pulley and dropping on the floor from there, all i did is took the dipstick tube out, cleaned the area very good, a bit of instant gasket around the o-ring and re fitted, left it overnight and drove off in the morning, after almost a year or possibly even more. no oil
worth checking IMO