As far as from what I read Geico does not do replacement cost, they call it "stated value" but it is not the same as "agreed value" that the collectors car insurance offers.
Pretty good article describing the differences: https://www.lelandwest.com/stated-value-vs-agreed-value-classic-car-insurance.cfm
I'd definitely read and re-read that GEICO contract and figure out which type of coverage is had.