Missing images from post source to publication

A series of old posts have broken images. Here’s an example post.

The source post references the image at http://matt.routleynet.org/uploads/2018/fe8bce4f92.jpg. In the post this is converted to https://matt.routleynet.org/6287/2011/fe8bce4f92.jpg which is 404. The change from “uploads” to “6287” is consistent with other posts, but doesn’t seem to work in this case. The image is available at the source “upload” url.

In the uploads section at micro.blog, there seem to be many broken images in the last 1/3 or so of pages (around the 2018 mark). I don’t remember this being a problem before, though may not have noticed.

I think these were imported from Tumblr. It was a while ago though, so I could be misremembering.

Any suggestions are appreciated.