I think that factories should have a scaled repairing feature for machinery that we produce; rather than moral being the only mechanism. So, if you have a tank nearly dead and you park it in a province with a factory it should repair faster than if it was elsewhere. Same goes for boats except a harbor is required as well. If you park your boat at the harbor point (where a boat would spawn when produced) and there is a factory in the province it should be repaired faster than out to sea. same for artillery, railguns, cars, heavy tanks, etc..