Fox Collectors

I was wondering if you can use ejector barrels with an extractor receiver. In other words are the barrels interchangeable and will the ejectors work?

Thanks

I am new to the forum and really have enjoyed reading all the interesting posts. I am about to buy my first Fox gun. It is a 16 gauge, 28", XF/IM, 6.25 lbs, #3516XX. I have two questions. Does anyone know how to find out what year it was made? And does a "professionally pinned" stock ...