Exhaust Pipe - 1981 Wr 175

I have a 1982 WR 175 (actually is a 125 with the 175 kit that was sold in 1982).
Unfortunately, the exhaust pipe is missing (it was sold as part of the kit), and I’ve been unable to find one. For this reason, I would like to rebuild one from scratch. In order to do so I’m looking for the exact measures of the pipe and a picture of the same.
There’s anyone that can help me?
Of course, any suggestion will be highly appreciated.
Thank you in advance

You mean that pipe ?

yes. That seems to be the right one.

thank you

hello lui
have modified a 125 rm 1978 pipe not so far from the pro circuit pipe and it works fine