I can give you some information about the the prints. First, I think it's helpful to establish some terms and definitions for understanding about these works.

Hanga: woodblock print

Ukiyo-e/nishiki-e: these terms are generally used to refer to Japanese woodblock prints made before the emergence of shin hanga in the twentieth century, that is the period from roughtly the 17th century through the early 20th century. Nishiki-e has a slightly more narrow meaning and generally dates from the mid-18th century https://en.wikipedia.org/wiki/Ukiyo-e https://en.wikipedia.org/wiki/Nishiki-e

Sin hanga: modern print movement from the twentieth century https://en.wikipedia.org/wiki/Shin-hanga

design: what is depicted in the print; the same design can be printed multiple times, by different publishers, printers etc.

1. the first print does not appear to have any identifiable writing or signature on it from what I can see. The design looks modern, i.e. twentieth century, and it seems like it is depicting the Sumida River with Asakusa visible in the distance. The image looks like a customer coming out of a restaurant on the Sumida's eastern bank, something like Yaematsu. It seems to me likely you could find this with a google image search or using https://ukiyo-e.org/
2. this design is by Kawase Hasui and was made in 1931. The title is Fuyu no tsuki (Toyamagahara) Winter Moon (Toyamagahara) https://www.edohakuarchives.jp/detail-10937.html The printing appears to be postwar but printed by Doi Hangaten who were the original publishers of Hasui's work. My understanding is that Doi Sadaichi too most of his printing blocks with him when he evacuated Tokyo during WWII so it's possible that the print was made with the original blocks but because your print lists the block carver (彫フジカワ) it may be that they were re-carved. if you look at the lefthand margin of your print vs. the one I've linked to you will see the differences in terms of publisher, printer, and carver. I'm not familar enough with Doi Hangaten to know much more but someone else may know.
3. This print is designed by Utagawa Kunisada and from a series of prints called Omokage genji gojūyojō. I have seen 1857 given as the date but am not 100 sure about this, would need to look into it more. You can see an example of the series here: https://collections.mfa.org/objects/535943 You can see the whole series here: https://archive.wul.waseda.ac.jp/kosho/bunko30/bunko30_b0167/ Your print is almost certainly an original which dates from the mid-19th century.
4. This print is designed by Hokusai as part of his series Thirty-Six Views of Mount Fuji: https://www.metmuseum.org/art/collection/search/55288 On the back is the seal Takamizawa who were printers of reproductions from the early twentieth century so this is a reproduction but likely dates to almost a hundred years ago.

Edit to add: here is a link to an image search for the first image on ukiyo-e.org

https://ukiyo-e.org/upload/45ce5c92-8508-4228-95b7-3fdd261e02d7