I was just asked myself the same question today, the instructions for my Constructo Albatross kit reads as if I need to secure the yards, booms and gaffs to the masts BEFORE installing, which doesn't sound correct. It has been a decade or more since I did any ship modeling and I am at that stage when I am installing all of the rigging hardware or tackle on both of the masts and was reading ahead a bit in the instructions and was not sure of how to proceed. My instincts say step both masts into the model, ensure that the angle of the masts are accurate and the mast is perpendicular to the keel, THEN install the yards, booms and gaffs onto those stepped masts. I have choosen not to rig the included sails in the kit as they are only printed on the sail material and not cut out. I do not have a sewing machine to do the hem and etc. I guess I should look into getting one, the OcCre kits that I have all have finished and darkened sails, which I will use. I did use the printed sails on a few of my past builds, Santa Maria for one.
Any insight answers would be welcome.
Thank You all.