angarthewhisperer wondered:

What lines ARE close to complete? If enough lines, close to completion, end will that throw in wrench in how long this open line list is?

Define "close to complete".

First off, you KNOW that Superman, Superman In Action, Batman, Dark Knight, Wonder Woman, Shazam and Shazam Family will virtually NEVER be complete. Far too many volumes of each of these are needed just to get out of the 1950s.

Of what's left:

GOLDEN AGE:
Robin is about 1 volume away, if you assume that the "complete" means the end of his run in Star-Spangled
Golden Age Spectre is one large volume (300 pages) away from completion
Golden Age Hawkman is 3 (normal-size) volumes away
Sandman is about 2 volumes away
Plastic Man is about 8 volumes away from the end of the Jack Cole run
Golden Age Flash and Golden Age Green Lantern are each well over 6 volumes away from completion (haven't done detailed mappings)
Batman In Worlds Finest and Superman In Worlds Finest are each just a volume or two away from completion.
Comic Cavalcade is about 4 volumes away from the point where it turns into a funny animal comic.
JSA All-Stars would take at least 8 more volumes to complete.

SILVER AGE:
All depends on where the Silver Age ends for you. To me, it varies:

for the Superman titles, it ends when Weisinger retires in 1971 or so.

For the Batman titles, it ends just before O'Neil and Adams begin their contributions.

For Wonder Woman, when she loses her powers and becomes Diana Ri ... errr, I mean Diana Prince, white-pant-suited karate expert.

For The Justice League, Vol. 10 is just about the end of the Silver Age (but I don't think that's the last Archive we'll see)

This means, that Superman Man Of Tomorrow, Supergirl, Lois Lane, Batman: Dynamic Duo, and Wonder Woman: Amazon Princess are all multiple volumes away from completion. As for the rest:

The Atom is about 4 volumes away.
Hawkman
is about 2 volumes away.
Green Lantern is about 3 volumes away from the beginning of the O'Neil/Adams "Hard-Travelling Heroes" run
Teen Titans is about 2 super-sized volumes away.
Metal Men is about 2 super-sized volumes away.
Flash is about 3 volumes away from the end of Infantino's run
Sugar & Spike is about 8 volumes away (but I surely would love to see every one of those 8 volumes)
World's Finest is about 3 volumes away from the point where it changes from a Superman-Batman team-up title to a Superman and whomever team-up title
Aquaman is about 6 volumes away from the beginning of the recently-reprinted-in-paperback Death Of A Prince storyline
Brave & Bold Team-Ups depends on what they intend to cover: if it will extend into when the book becomes all Batman team-ups, then there are 10 or more volumes to go. Otherwise, its one more and done
If they ever decided to go beyond the Kirby issues of Challengers Of The Unknown, they would need another 6 or 7 volumes.

BRONZE AGE
Legion is about 4 volumes away from meeting up with The Great Darkness Saga Deluxe Hardcover
New Teen Titans and Kamandi, in light of other editions of that material, can be considered dead lines right now IMFAO.

I'm sure I missed a few, but that covers most of 'em I think.