Hmmm . . .
To begin, top_man, I think that you mean: ‘He was to receive $1,000 FOR each month IN the job,’ and ‘He was to receive $1,000 for each month . . .’
No, it’s not a passive-voice structure. It is a member of a ‘family’ of structures – less and less common now – that are not part of the sixteen-tense system that is taught to students. The family contains sentences such as:
I was to be shot
I was to have been promoted
I have a chapter in my grammar that details these. If you can get the moderator’s permission, I will post the chapter.