Aqueon still makes the 40L. If you live within driving distatnce of the Boston area you may be able to buy one from kensfish.com. He does not ship them.
https://kensfish.com/pages/contact-us
I have a huge fish store near me that would have them. Not cheap, but reliable. I am in Westchester County, NY.
https://kensfish.com/pages/contact-us
I have a huge fish store near me that would have them. Not cheap, but reliable. I am in Westchester County, NY.