Pete Christlieb’s Berg Larsen is a stainless steel 130/0 SMS which actually measured .122 at the tip (Bergs’ measurements are not known for their accuracy). The Drake Christlieb mouthpiece was made in consultation with Christlieb to match his mouthpiece’s characteristics. Therefore if your search for a metal Berg proves fruitless a Drake Christlieb in a .120 opening would be an excellent alternative. They are around £350 new so you should be able to get a used one within your price range.
Hi. I have a steel Berg Larsen 130/0 M, and also a Drake Pete Christlieb 120. Both would appreciate a new home. No original ligature though, I remember playing the Berg with a Rovner.