Nissan will be your best bet, but do not know what the price will be, if too dear then pop along to your local welding shop that does ali and get the perforated bits replaced with new pipe, it can be a larger size that slips over the existing, that is not a problem, but make sure there is absolutely no debris left inside, my ali welder guy managed to weld an expanded plate evaporator in a commercial fridge that the chef stabbed with a knife while trying to get the excess ice of it (he will not do that again) this repair was done 6 months ago and still holding, Rick