RE: FMS P51 SPINNER & COWL PROBLEM
No big deal...
Unscrew the grub screw holding the prop shaft onto the motor shaft.
Then slide the prop shaft back further. If this is not possible, use a drill bit to clear a bit more material from the prop shaft.
The plane flies just fine as is, provided the shaft is locked down well.
BTW: I hope you will not attempt to fly this plane without first being instructed on a regular trainer.