I kept trying to work out the problem, but couldn't locate the source, so my C330 sat on the shelf for awhile, only being used occasionally until now. Thing is, this is a really nice camera that takes otherwise exceptionally sharp images, so recently I began trying to troubleshoot again.
Zeb took a look and showed his folks at Blue Moon Camera and Machine. They reinforced the idea that this is indeed a processing issue, and that they had seen the problem themselves occasionally with Paterson reels. Other suggestions from the internet involved inversion method and the amount of tightness on the reels. Armed with all of that knowledge, I ran a roll of Tri-x through it again, but this time made an important discovery: The lines showed up in the first few frames of the roll, but not the last. They were somewhat visible in the middle. If what I'm seeing is correct, that means that, for this roll anyway, the end loaded first didn't have the problem, and the end loaded last displayed those lines.
|First frame on this roll, last one loaded on the reel.|
|Last frame on this roll, first one loaded on the reel|