Sorry, but you do not need a harmonic balancer.
If I correctly understand your timing problem, what you really need is:
a new crankshaft timing belt pulley
A new key pin
and possibly
A new crankshaft.
Been there, done that....
The "Harmonic Balancer" is actually nothing more than an accessory drive pulley that is attached to the face of the crankshaft timing belt pulley with five bolts.
It can be fixed quick and dirty with JB weld, but you can count on being left out of your Grandfather's Will if it fails.
Wishing I was related to the Tappet brothers - Click and Clack, I remain,