Now im confused
If the 125 pipe is a TS 125 kit pipe it should fit your TM 125 . The 125 kit pipe is better than the original TM pipe but not as effective as an RM125S pipe or even a RM 125M pipe.
The bigger pipe does look like a TS 185 kit pipe though , do you want a pipe for a TM 125 ?
I have found the vintage iron pipe works best on TM 125s
but if you order one phone first for a confirmed postage price