Want to preserve old "Homemade" content (Crosspost from Digitpress)

Here's something I've been curious about.

For a while I've been wondering about the various "game development kit" style apps for retro consoles.
This is rather broad, but basically I'm referring to stuff like Famicom BASIC, Dezaemon, RPG Tsukuru, and whatnot.

I've tried looking up videos on NicoNicoDouga and Youtube, and the results vary, but are overall pretty interesting.
However, it seems on the subject of true archival it's a different matter entirely.

The 32-bit gens onward (Sega Saturn and Playstation in particular) appeared to have very good archival because of the combination of the internet, external memory cards, and tools like the DexDrive which dumped memory cards as computer files. But anything from earlier than that, and you basically have next to nil unless it was made in an emulator. And the Famicom BASIC stuff isn't really emulated at all, so...

Has there been anyone around here who may have been consciously trying to collect and preserve these sorts of things? Grabbing things such as Famicom Data Cassettes, Dezaemon SFC carts and ASCII Turbo Files digging through them to figure out what homemade contents are in them?
A lot of Satellaview 8M Packs have been dumped which have turned out to have homemade RPG Tsukuru 2, Sound Novel Tsukuru, and Ongaku Tsukuru Kanaderu homemade data, and work has been done to have them emulated on Luigiblood's BSNES fork;
http://bsxproj.superfamicom.org/
I haven't had the time to sort through them all and figure out all their contents, but it's possible they may have interesting homemade games.

But that being said, I haven't much luck grabbing anything else. I've googled Japanese terms to see if there's any good preservation sites for these sorts of things in Japan but have had no luck, unless going into the 32-bit-era.
I'm currently particularly interested in trying to grab SFC Dezaemon and Turbo File contents, as those would go along with my Satellaview 8M Pack dumping quest to further complete the more obscure side of the Super Famicom. I would of course love to hear about anything on Famicom BASIC that might be of interest as well.