I was wondering the worth of my New frontier in MINT cond. 6 inch BBL and LR and Mag cylinders.

From the twenty-fourth Edition of the Blue Book Of Gun Values:

100% =$450.00
98% = $375.00

I posted both values as I didn't know what "Mint" meant to you. 100% = NIB, never fired, no handling marks.

Ka6otm