a post house good hardware converter should give you the best results.
do you know the type of converter your house used?
the way to do it is to output your old QT with your new mix to NTSC Digibets,
then put that thru the converter.
if they didn't do that, then maybe they were just using software, which you could do yourself.
(it almost sounds as if they just did it in FCP, which will give noticeably jumpy results, so maybe you should try another place.)
Nattress gives good results
as does Compresor, with the frame controls set to "best".
a little bit better than Nattress, but takes a LOT LOT longer.
oh,
11G of DV?
that'd be about 52mins
good luck,
nick