Go ahead and put a front crank seal in, and make sure the seal surface on the dampner is not grooved. If it is, you can have a sleeve put on at the machine shop, so the new seal won't leak. By sure to put RTV on the crank bolt, as they can leak oil from under the bolt head by running down the crank between it and the dampner. (when I was at Toyota, I saw that problem several times.)
Check oil pump clearances, and repair if needed. How's oil pressure ? Maybe time for pressure regulator ?
Me? I'd look at the bearings while I was that deep into it.
Timing belt ?