I would go along with the crankshaft seal. Mine leaked like mad, but I replaced the camshaft one at the same time. It's not too big a job if you have a garage. I found that getting the gearbox spline back into the clutch an absolute nightmare. I seemed to struggle for hours on my own trying to get the spline in. The way I managed it eventually was to leave the clutch plate slightly loose on the flywheel and then tighten the nuts up fully once all was back in place by using the hole for the water pump/alternator pulley before I put it back on, which took only a matter of minutes. Just a matter of turning the flywheel to bring the nuts up to the hole where they are easily accessible. It's one of those rewarding jobs, a tiny part, but you do get a good sense of accomplishment when you have succeeded, and you also get a greater understanding of the front end mechanics, gearbox, suspension, steering etc.
