My apologies for the quality of the scan. As of yet, I have not been able to obtain a better copy of this letter.
[*] The only support that Rav Moshe signed this kol korei is the addendum to Igros Moshe, (vol. 6) O.C. 4:89. The fact that this is the only addendum in any volume of Igros Moshe makes it somewhat questionable.