The INGLIS copy of the Hi-Power was "reverse engineered" in Canada during WWII based on a pistol personally owned by a Chinese Nationalist General. A gunsmith can give you the answer, but I have always understood that interchangeability is "close, but no cigar".
Having said that, if the Inglis is in good shape, it will last long enough for your grandchildren to wear out.
I own an Inglis, and my son has a wartime FN. I havn't really had to check out parts interchangeability, yet.