Originally Posted by
brian3069
More than likely your bottom bracket is Swiss threaded, sourcing a replacement can be difficult and expensive. The rounded flats on your cup is a minor issue. In the link below Sheldon Brown describes how to make a tool to remove, or install a fixed cup.
https://www.sheldonbrown.com/tooltips/bbcups.html
If it's a Peugeot-BB-made-by-Solida, six lines in a star centred on the axle hole mean english, a ring around the edge mean swiss. Both are LH, you can match it up against a known cup to make sure.