Schwinn serial number trouble

[Gyratingyak]

I bought a schwinn a while back and was told it was a 1957. I got it for 40 bucks from a man who sold bikes from his house. I found the serial number on the left rear drop out or rear axel. the serial number is M151454. I couldn't find it at all and wondered if any of you know what year it may be from. Thank you for any information that helps me. Before I got it he had changed the sprocket and rims. he also painted over the badge on the front

 

[Jpromo]

I'd venture to say it's a '61 since it has the letter followed by 1xxxxx I know the records don't quite make it to 15xxxx but that would be my thought.

If you post a picture of the complete bike, as well as a macro shot of the serial number, it can probably be best solved that way. There were many changes that took place between the late fifties and early sixties such as chainguard, seat, fork decals, frame decals, pedals, etc.

 

[Gyratingyak]

sorry bout the fuzziness, my camera is pretty bad and I put my money into old rusty stuff