Post in forum #235250 - Obtaining the highest-resolution images from Tumblr
Dogenzaka
Privileged
7 months ago

Munkelzahn said:
Search for the image with Reverse Google Search.
If you're lucky, someone has reposted it, and you can get the direct image link that way.

edit:
please make the posts you listed clickable

Also, if the artist had some text in their post such as a description or whatever, you can google search that and find reblogs that are still intact. This has helped me a few times.