If anyone is interested, I found a copy of the Data extension by Oskariok. It is for version 1.0 of Small Basic and has its own installer. Both included in the zip below, along with the resulting Data.dll and Data.xml which probably work without the Data installer. You would need to uninstall SB (maybe take a copy of your current lib folder first), install SB version 1.0 and then install Data extension or copy the dll/xml to lib folder (in this version of SB you may need to create the lib folder). I have not tested, but it's there if anyone wants to have a go. As I mentioned before, the resulting dll is obfuscated and I cannot update to current SB version.
Data by Oskariok (version 1.0 SB)
Finally, if there is anything in this that is really interesting I would be happy to consider implementing something similar in LitDev extension if it fits into the ethos of complementing and working fully with standard Small Basic. I probably didn't at the time since I didn't want to copy other extension ideas, but since clearly it is not maintained I would be happy to now.
EDIT
It is possible to extract a Small Basic version from its msi without uninstalling/installing so you can have multiple versions (msi is just a zip). This means you can easily test an old version and you can switch between versions (including sVB) in SB-Prime using Advanced->Options->Small Basic Installation Path, or just use the different versions of SB.exe.
Below is a zip where I have done this with SB_v1.0 and test the Data extension.
SB1.0
Data by Oskariok (version 1.0 SB)
Finally, if there is anything in this that is really interesting I would be happy to consider implementing something similar in LitDev extension if it fits into the ethos of complementing and working fully with standard Small Basic. I probably didn't at the time since I didn't want to copy other extension ideas, but since clearly it is not maintained I would be happy to now.
EDIT
It is possible to extract a Small Basic version from its msi without uninstalling/installing so you can have multiple versions (msi is just a zip). This means you can easily test an old version and you can switch between versions (including sVB) in SB-Prime using Advanced->Options->Small Basic Installation Path, or just use the different versions of SB.exe.
Below is a zip where I have done this with SB_v1.0 and test the Data extension.
SB1.0