http://download.scratch.mit.edu/source-code/ScratchSkin1.4.zip\.

There’s not much wrong with this link. Click it. Then remove the trailing slash. It downloads. 
How about posting that Installer script here. I’d like to see it. Because that’s all we’re talking about: saving an Installer script to disk for future download. SqueakMap server makes that process staggeringly unreliable and complicated. 
It would be easiest to just store them in a directory accessed by the Squeak FTP client to download them. That doesn’t have the helpful meta-information and labeling. But that’s exactly the same thing. (I fixed that FTP problem ages ago. I think I put something in the Inbox. I don’t remember clearly.)
All we’re talking about here is Installer scripts. SqueakMap may have once had an all embracing, extensible design, but the use case has been reduced to this one alone. Installer scripts won. 
This kind of thing could be knocked together pretty easily with Seaside: uploading files to download later. And really, since SqueakMap model is in every image, it would be easy to subclass and extend those classes, so that the ReferenceStream was a catalogue of Installer scripts explorable through the SqueakMap UI instead of that categories and package info gibberish. Who wouldn’t want to down a file that allowed them to explore 100 Installer scripts using the SqueakMap UI? 
I would imagine all that stops such a sane course is archiving a catalogue of legacy projects which can no longer be loaded into contemporary images. 
Chris 

Nina Haaaaaaaagen
https://www.youtube.com/watch?v=JWzPcDtZZZo