silver percy

Yes, there has never been anything that's ever said there was a Plarail Silver Percy and Bronze Diesel. I wonder where that made up story came from.

You might be getting confused with the Wooden Railway range. They made set that included Gold Thomas, Silver Percy and a Bronze Diesel

I think the existence of Learning Curve's Wooden Railway Silver Percy and Bronze Diesel and Tomy's Plarail Gold Thomas may be part of the reason why someone has assumed that Tomy also made a Plarail version of those two engines. People want to believe there are gaps that need to be filled in for some reason.

this was only released in japan-right?
am i correct in saying this?

Correct. Tomica products are only released in Japan.