Help with Marking on inside of helmet

[cerick1450]

Hello

 

I was given this by a neighbors family. Their father was a veteran of WW2 and Korea. They believe this is his helmet from Korea. Any idea as to what the C-151 may stand for?

Thank you

 

 

[cerick1450]

one

more

 

[Raddock]

It’s too short for a laundry number so possibly G company, 151st combat engineer battalion, or maybe there were some other 151st designations at Korea