Blimey! Seems I am sadly lacking in that era of the episodes. <blush!>
Looks like I can only help with 1 or 2....
Now in my JAM upload folder - http://www.mediafire.com/?17rnd8u0bpx3v
1990.04.07 - sneezes - 28.3mb - noisy, muddy sound, like an AM radio
same and mine's only 4.7MB
1991.02.02 - telepathy - 22.1mb - very "thin" sound, sounds like a mediocre 70s recording.
I don't have it
1991.02.09 - bags - 13.9mb - very poor, muddy sound.
I don't have it
1991.02.16 - A good part to play - 27.9mb - very thin sound again, like telepathy above.
I don't have it
1991.02.23 - Biscuits in bed - 7mb - no intro, and very poor sound
Same as yours and 6.8MB
1992.01.25 - This And That - 27.7mb - thin, muddy sound
I don't have it
1992.02.01 - What - 13.9mb - very muddy
sound
Same as yours and 13.5MB
1992.02.22 - Advertising - 13.7mb - very muddy
Same as yours and
1994.01.22 - Norwitch - 14.2mb - very muddy
I don't have it
1995.02.11 - Dragons - 13.9mb - very muddy
I don't have it
1996.02.17 - Burns - 28.4mb - thin and muddy sound
I don't have it
1997.01.04 - The Scotsman - 7.1mb - very muddy sound
12.9MB Not as muddy as the others but the speed is too fast - NP and everyone sound like they're breathing helium
1997.07.19 - Manchester - 27.6mb - muddy and unstable, "AM radio" like sound
I have two versions, 27.5MB and 11.9MB both stereo and sound pretty good to me.
1997.08.09 - Flying By The Seats Of My Pants - 6.9mb - very muddy sound
Slightly muddy but still very 'listenable' and 12.9MB
Would have made life easier for me if you had quoted total episode number or series/episode
Thank goodness for Dean's ep guide

--
Cheers
Don __o
\<,
.....O/ O