Unknown rebuild specs

The first thing I would do, is get a light, see where the timing is now, pull some more in it if it doesn't have any more than about 12 or so.....maybe try 16 or 18. If that makes a difference, you know it needs recurving. Beyond that, you're simply going to have to experiment with different curves. Maybe if you run a compression test and post those numbers, we can give you a decent starting point.