Should I enter tax money withheld but not marked in 1099-Misc. form I received from a lawsuit settlement. Payer didn't have SS# at time check was written & will not help?

Received a lawsuit settlement of $774 & a check for $504 with a incomplete 1099-misc. form  / statement. Payer did not have my SS# at the time the check was written. How do we get credit for withholdings (35%) payer withheld. Can we assume 28% was held for Fed. & remainder for state?