Hello,
I just made an account to reply to this thread. Hope this random new account necro-ing a post is ok.
I believe I own the cartridge for the gold version, and my cousin has (or had) the version for silver. They are just a bootleg translation of the original japanese version.
Just want to share how we got them in case it gives extra context and information about the roms.
We were on a sky trip in Andorra.
My father bought them on a small electronic store as a Epiphany gift (In Spain kids get presents for xmats on the .6th of january).
This was on the year 2000. I do remember that we had them Magically (by my kid's brain) before they were in stores.
They came in what looked like complete genuine nintendo boxes, complete with manual and paperwork.
The cartridge is just black plastic with a non genuine sticker, no marking and not even a security screw.
probably this one?
https://www.avid.wiki/Pikachu_Inc.