There were two types. The M45D/F turret shield and the M45C turret shield. The M45C turret armor with the large “nose” is not available. That’s why I added my HOW TO conversion to this thread. The ones you have are the M45D/F turret armor with the small “nose”. You would have to convert them. In Vietnam roughly about half of the quad 50’s had the M45D/F shields and half of them had the M45C shields. If you want to replicate a particular quad 50 used in Vietnam and you don’t want to convert your shield, I would choose one that had the smaller “nose”. I hope that answers your question.