Where does one find an odd sized P-trap for home vanity sink? The compression nut thread size of the outlet side of the J trap looks to be 1 3/4". A 1 1/2" nut is too small and 2" is too big but the inlet side of the trap is a standard 1 1/2". The trap is in good shape but the compression nut has stripped threads. This home was built in the early 1950's and this is the original plumbing.

Back then we trapped our lavatories at 1 1/4" but why hassle with it? The trap's over 50 years old, simply replace it . Good luck, Tom