I'm inspired by your posting. I found an older Blickman Touch 'N Brew at a local Used Restaurant Equipment shop, and the guy wants $200 for it. The thing is definitely not in mint working condition, mainly just missing a couple of the little connection lines on the top. I'm don't have welding...
I very quickly found a few places online that sell these tanks. Do a google search for "plastic inductor tank"
http://www.plastic-mart.com/item.aspx?id=5813
http://www.tank-depot.com/productdetails.aspx?part=N-60214
http://www.usplastic.com/catalog/item.aspx?itemid=25197&catid=513
Enjoy!