Don't know the record or have any info bout the singer, but here is what is listed as a Studio 1 label 7" (info from Coxsone's Music)
God I God I Say - Keith Wilson DSR CN 4347-1
God I (Version) - Keith Wilson DSR CN 4348-1
Apparently Cedric Im Brooks covers the rhythm on his Studio 1 LP 'Im Flash Forward'. If this is correct I'd guess his version is either titled 'Walking Through' or 'Free Man'.