Little explanation.
b. we know partial WIF of privatekey as nonce - we can use Monte Carlo together with LLL
c. recentering for partial integers plus BKZ or LLL.
becouse: IF OP has partial WIF example knowns MSB , not known middle, and Known LSB - it is easy even for 23 missing characters.
Post Scriptum: depends how much MSB with LSB we know - maybe we need implement enumeration.
Do u mean that you can use Lattice attack only with one signature? Have u sources or studies to show about this attack?