I have an LB Stratos nearing completion, they are working with a door to door crater / shipping service and assure me it will be the 2.5% duty + 10% tariff.
On small shipments I urge everyone to request a full breakdown of charges from couriers, I recently had Hewland gearbox spares shipped from the UK, DHL stated I owed $857 in tariff charges (~40%), when I requested a breakdown I saw they had applied 3 different tariff rates, cumulatively. I then disputed the charges and it came down to $307, which equated to the 25% I was expecting. Government tables for HTS codes and tariffs are readily available online, so with some homework one can ensure the vendor is appropriately describing the parts.