Schrade Paratrooper

[Geoff Ward]

Hello all, Just got back from a local gun show where I was offered what appears to be a Schrade Paratrooper knife. I have learned that the WW2 pieces had a brown Bone jigged finish, and the later post WW2 went to a Black synthetic grip and then eventually a black finished metal which is textured to look like bone.(Currently being reproduced) another difference I have noticed is the Earlier versions featured a swivel bale for a securing line or clip. I was hoping someone could help me determine the difference between a Model # 155 and a M2 and an approximate manufacturing time. Sorry for the bad cell pics I have tried to enhance them to get a better look at details. any help would be appreciated!.

Thanks in advance

Geoff