I'm looking for some help identifying the precancels on the stamps in the attached image (if, in fact they are precancels). I'm a long-time collector of U.S. stamps (50+ years) but only recently "discovered" precancels. I'm a little embarrassed to say that I was one of those who thought a precancel made a stamp worthless. It's only recently that I saw the light and came over from the dark side. Now I'm rummaging through my boxes of extras and discovering all kinds of cool stuff.
Anyway, I've been cataloging a pile of precancels and the bureaus and locals are falling into line nicely. But then these items showed up:

Here are my questions:
- I'm unsure of the 18c Washington because it might be either a precancel or an overprint. The wording was clearly added to the stamp after the image was printed.
- I'm almost positive the 9.3c Mail Wagons and 5.2c Sleigh are precancels but I have never seen a classification for lines only precancels. I'd appreciate some help with putting a type number on them.
- I think the 1c Dix and 39c Clark are ordinary cancellations but the gaps in the lines threw me. Is it possible these were precancelled with a roller?
- Ditto the 4c Americana. There is a trace of a third line along the perforations at the bottom. The lines appear to be pretty well aligned with the stamp which hardly ever happens with a regular cancellation.
Thanks in advance for the help and if anyone can provide a resource for identifying lines only precancels, I would sure appreciate it.
*** Moved by Staff to a more appropriate forum. ***