Ok, first off let me say I know nothing about old bottles! But my husband found a old bottle and I really want to know its history! It is a larger dark green bottle, with a long neck. It has a horse shoe/U shape on one side of it. There is also one single letter "F" on bottom. It does have a mold seam running up both sides but it stops at the lip of bottle. Then the lip has its own seam that does not meet with the seam running up bottle. I hope this makes sense. I'm going to try to add photos, we shall see how that goes!