Hello. I SUSPECT that they would be compatible, but if no one knows here, you might email Kurt Wickmann or Wayne Novak at their sites as they are both well-known Hi Power 'smiths. I believe Mr. Richard Heine posts here and he, too, is a wizard on the BHP. He might have the answer you seek.
I seem to recall reading somewhere that the Inglis P-35's were made using English measurement blueprints, as opposed to metric as used in Belgium. The original blueprints were supposedly smuggled out of Belgium by some factory workers who barely escaped the oncoming Nazi armies. They then helped set up the production lines in Canada. It's sort of like the various contract versions of the FN-FAL rifles. Maybe the dimensional differences are small enough to not cause any problems, but I'd certainly check with a smith experienced with working on them.