Unlike national television and movie company logos, the bumpers and continuities for networks and local stations are not always readily available.
Online postings of off-air vintage recordings are plentiful, but there still remains some continuities, bumpers, etc. that have yet to surface.
-when the impostor is sus
The early days of FOX Kids used animations to mark the beginning and end of a commercial break. One curious animation involved an Old West type shootout between a cowboy and three bandits or "villain"-type cowboys. He hits all three, which turn into something resembling talking pieces of popcorn. When the commercials are over, the "popcorn" sprouts back into the outlaws.
Some people remember it being seen on Saturday Morning airings of "Bobby's World."
- Materials from WXTV 41 (Spanish language network out of NY/NJ area)
So far on YouTube, surfacing footage includes: Star-Spangled Banner video used by the station (WXTV used the same footage as WPHL in Philadelphia and begins with an acoustic rendition that fades into a full orchestra). Chicago's Fuzzy TV Memories has the "SIN" (Spanish International Network, pre-Univision) opening logo that would have been seen on WXTV. Audio from a 1970s WXTV sign-off also exists online. 
- Materials from WNJU 47 (Spanish Language network out of NY/NJ area)
- WPIX "Popcorn" technical difficulties screen
Some viewers recall that when WPIX, Channel 11, in New York experienced operating difficulties, they would use a slide/graphic containing a giant 11 with Hot Butter's "Popcorn"  playing in the background.
- Jimmy Neutron Show Interruptions (Early 2000's)
While promoting The Adventures of Jimmy Neutron, the title character of that show appeared in the lower-right hand corner on the day of its premiere, and using one of his inventions temporarily did things to the show, including (but not limited to) rewinding and fast fowarding the episode, making it have VHS static and glitchy voices in the process, giving characters his hair, and turning the shows into puppets. Only a single image of one of these has surfaced on the internet.
- HBO (Early years, 1972-1980)
Material from 1977-80 has been found, but as for the 1972-1976 materials, all that has resurfaced over the years is a set of very rare Feature Presentations from 1975, in Computer Image Corporation's Demo Reel (appearing at 6:19-8:46), as well as their broadcast of the 1973 Pennsylvania Polka Festival.
- Showtime (Early years, 1976-1980)
Material from 1979-1980 has been found, but as for the 1976-1979 materials, At least one video from this era is known to exist, taken before an airing of The Other Side of the Mountain from March 14, 1979. https://www.youtube.com/watch?v=nB5KLOGKVYI And another, which is a compilation https://youtu.be/MSPGBNMF6b4 Also, https://youtu.be/fxJFxytj5gU The Sign-off, https://youtu.be/ZePlk1qV_TY Some stuff can be found in the Something’s Coming Something Great promo & the full Sign-off as found in the 1981 Showtime reel, https://youtu.be/Es3-OsvLcvU
- Take 2 (Channel, 1979-1980)
One of HBO's channels, of which nothing has resurfaced.
- Festival (Channel, 1987-1988)
Another one of HBO's channels. Same as Take 2.
- You're Watching Disney Channel Adam Lamberg Wand Bumper (2003)
To be announced.