It can take a while depends on a few things... Budget, Research, Subject Size, Initial CAD, Refinements to CAD Work, Tooling/Mould layout, Tooling at Factory, Test Shots etc...
For example, a single-seat figure could take up to a year till release if all the stars aline! From memory, the Junkers D.1 was WNW fastest release from the start date to release date. It helped as the tooling company was really switched on and there wasn't too much back n' forths regarding adjustments.