Hello and welcome.
That's a great find of you, thanks for reporting us. I'm interested to check them, you're free to upload them somewhere, like on Dropbox or similar websites, and share the folder with those archives.
I know about the existance of this Team_UK, it's from at least 20 years ago; I know about it especially from a Mario Cart vehicle (yes, written Cart, and not Kart) made from scratch which I have (not present in the files you show to have, though).
If you still have contact with your team then ask them for permission and then upload these vehicles on MM2X in my opinion. If you do not have contact with them then its ok to upload them without their permission, although credit is still necessary to be given.
He said to have been part of that team and has some of their creations, and after all these years, he's free to spread them in name of his team. It's more than enough. Also, try to contact again people that probably hasn't heard since ages would be pretty much impossible...