Tuning Does anyone make an aftermarket airtube Gen 1 marauder?

alumnium tubes are like gold

unlikely to find one unless somebody selling a used one

You could have a machinist shop make one, but will be very costly as they have to use a cnc mill machine to cut the holes and slots

and also a lathe to thread the fill side. Plus paint/anodize it and you would need a nylon mds hammer as the stock steel hammer will damage it.