Well, if Alembic has any pickup seconds, you could probably get a pair for around $100.
If you're thinking resale, a '90 Essence with some finish issues is probably going to sell closer to $1000 than $1500. I don't think any attempt at refinish would add to the value at all. Though rare, solid-finished Alembics don't seem to be worth as much as wood grains.
If your consideration is financial, you are probably best served to get some pics and sell it as is. If all it needs is pickups, I believe that everyone here knows they can get them from the factory for $100-150. Unless damage was done when the old pickups were removed, the new ones should just clip in, so installation is a no-brainer.
Good luck-