Hello Rosco,
Nice finds. From the pics, it looks like the "E" in "WE" is doubled. I don't see much in the way of doubling in the other pics. I took a look at lincolncentresource.com but could not find a match to what you have posted. Try searching for 1972 doubled die Lincoln cent to see if you can find a match anywhere. Would be interested in what you find . As for the die crack, I can't tell from the pics if the line is raised or not. Since another scratch is also displayed on the cent I would lean more towards it not being a die crack and more of pmd; but, honestly can't tell from the pics. Nice find on the 1918! If I find any close match to your 72' I'll update this reply.
The 1972 looks like it may be a winner. It is so worn, however, that the premium will be limited. The 2015, on the other hand, leaves me with doubts. I can not tell from the images provided whether the lines are raised or incuse. The lower lines may be a strike-thru, but again, I can not tell from the images.
Yeah, the nose lines I figured were definitely PMD on the 2015. The forehead though just looked different from a scratch, unless it happened a while ago and has just worn down, but even then... And yeah, the 72 is definitely worn, which doesn't help. Appreciate the input though everyone!