Steve,
1. you say the dealer has a FX-1 on site,..........well, take that mast until the correct one shows up!
2. I would not touch that mast with a saw,..this is not your job,......you paid for a complete boat,..not a kit boat.
3. Will cutting the mast effect the warrantee?
.....let the dealer handle it,...they get paid for this stuff.
Bruce
St. Croix