I found this U4205 at a thrift store last night - marked at $19.99, but with my "club card" on Thursdays, it gets me 25% off.  It's pretty dirty, but in very nice shape overall.  I'll put it in line to get a teardown, for sure.  It's funny - I was looking at this thread just the other day and saw the pictures of this model, and thought to myself that I would love to find this non self-propelled machine... then two days later here it is.  The universe works strangely sometimes. 

Austin, I found a model like that Teal Concept on Craigslist sometime a year or two ago, for pretty cheap and I tried to do a restore -- but it was too far gone, and in pretty terrible shape.  I think it's a model U3341 if I recall correctly.  I kept a handfull of parts for it, because I hope to find another someday, but pitched most of it.  I love the simplicity of it, how it's a "bottom of the line" machine.  I don't love the cord winder on Concepts - I prefer a longer cord generally, and they're a nusicance to deal with when disassembling the machine.  Yours seems to be in lovely shape!

-Fred