I've been in the same exact situation, and it's incredibly difficult to find a replacement poly/acrylic
tank. I would suggest to search every stone and leave none unturned, and look for an Erl clone.. just to get the
tank, and it doesn't hurt to have spare replacement parts. I also suggest, and it's definitely worth a try, contacting Von Erl for an authentic replacement
tank.
info@vonerl.com
I've gotten several replacement tanks from them, even a SS tank.. for free. Ask nicely, and you may be lucky. They do not accept any money for the tank or shipping. I know you don't have an authentic Erl, but i think it's worth a shot. I dont regret spending $$$$ on the Erl way back when, especially considering the amazing customer service for an item they haven't made or sold in quite a long time.
How are you liking it?? I'm with you on the SS tank, I like to be able to see how much juice I've got left.. but it's awesome to have in an emergency.