I know quite a few of us own and use these.  They're no longer being made.  The 20/28ga head on mine developed a problem.  Contacted them and was told to send it in, that they had repair parts.  I did, enclosing a check for $25 to cover repair and shipping, and a note to let me know if that covered everything.  (When I asked how much it would be, he said just cover postage!)
Well, about a week after sending it, I got it back today.  Cost about $7 to send it priority mail, and the package included a $10 bill as a refund!  Don't know how long the parts inventory will last, but good to know we can still get them fixed.