Bulova 1964 -Non-Conforming

Very faint "M4" barely visible on the caseback cover - barely readable because it's worn down. I love the cushion case with Florentine pattern, but have not seen this with a 214H railroad movement - either it's less common, or perhaps a frankenwatch. Unknown history except ebay seller claims NAWCC membership and vouches for the legitimacy of the watch (for what that's worth). I'd love to know more about it. Seller says the movement hums but the hands don't move - so I assume I'll be looking at a significant repair cost for rehabilitation. Thanks in advance for your review.