What year is my skip tooth J.C. Higgins???

[old&crusty]

I was wondering if anyone could tell me what year my newest project is. Its a J.C Higgins skip tooth and the numbers on the bottom read 57155. Any information such as year, model, value or anything would be greatly appreciated.

 

[Nickinator]

Before 51 is all I can tell you with that springer

 

[Jpromo]

Above the serial, there should be a letter designation like MOS-?
That question mark should be the letter that could help figure out the year.

 

[old&crusty]

The only part of the lettering I can see is "-N".

 

[1speedJam1982]

the N would indicate it being a 57 I belive