JB,
You cannot adjust the position of the hammers. You can only move the tines or the pickups.
You have five ways of moving the tines:
1 - fiddle with the "timbre" tone-bar mounting screw
2 - fiddle with the "escapement" tone-bar mounting screw
3 - add or remove shims from the harp supports
4 - slide one or both ends of the harp forward or backward (this adjusts the "strike line")
5 - if the tine is mounted off-center, loosen the tine-block mounting screw, and align the tine so that it is straight
You have two ways of moving the pickups:
1 - loosen the screw, and slide the pickup a tiny bit forward or a tiny bit backward
2 - if the pickups seem abnormally high or low, you can very delicately bend the aluminum tang to get the pickups to sit right (straight is best, but... you gotta do what you gotta do. Be careful not to break the pickup bobbin off the tang.)
In the situation that a tonebar is leaning down so much to get the tine facing the pickup, bend the pickup to sit higher, and the tonebar won't be leaning down so much that the tine block is pinned against the rail.
Are these new tonebar grommets or old tonebar grommets? New grommets will fix (or change) lots of positioning issues.
To re-install the tuning spring, you should remove the tonebar and tine from the harp, and hold it steady in a bench vise.
Sean