I found another thread about the air tanks that has a link to the clippard store, here's the part that we need, I think...
http://www.clippard.com/store/displa...?sku=AVT-32-16
To find a bimba distributor, try here:
http://www.bimba.com/OrderInfo/Distributors/
but it may be wise to see if there is another distributor somewhere that has the cylinders you need in stock already.