[tin 1.9.x] problem with Multipart/Mixed and text/plain iso-10646-ucs-2 base64 parts

When reading a gated malinglist I noticed that tin didn't display a
text/plain part in an multipart article. This might be related to 
iconv (linux glibc 2.7 iso-8859-1 env. and linux eglibc 2.11.2 utf-8 env.)
not knowing(?) iso-10646-ucs-2 (but ISO-10646/UCS2), but tin puts (too few
bytes of) garbage on the screen instead of expected '?'s. Anyone willing to
look into this? The mime structure is the following:

Mime-Version: 1.0
Content-Type: Multipart/Mixed;
  boundary="Boundary-00"

--Boundary-00
Content-Type: text/plain;
  charset="us-ascii"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

foo

--Boundary-00
Content-Type: text/plain;
  charset="iso-10646-ucs-2";
  name="bar.txt"
Content-Transfer-Encoding: base64
Content-Disposition: inline

/v8AuwBKAPYAcgBnACAAbQD2AGMAaAB0AGUAIABmAPwAbgBmACAARgByAPwAaABzAHQA/ABj
AGsAcwBiAHIA9gB0AGMAaABlAG4AIAB1AG0AIADkAHUA3wBlAHIAcwB0AGUAcwAgAFYA9gBs
AGwAZQBnAGUAZgD8AGgAbAAgAHoAdQAgAHMAcAD8AHIAZQBuAC4AqwAK

--Boundary-00--