For those interested I have written a small program which takes the
large MPCOrb file and reduces it to a small file of asteroids based on
user date and magnitude settings.

Simply select a date and maximum magnitude, the program calculates the
asteroid position and determines its magnitude on the specified date.
Then it writes to a new file(MPCOrb.dat) only elements with magnitude
less than specified by the user. By doing this once a month, one can
keep the size down and asteroid up to date. The process takes 10 to 15
seconds to complete on my 2 year old laptop.

A 16 magnitude setting showed 1348 asteroids, file size 271k.
A 18 mag setting gave me around 10,000 with a file size a little more
than 2 meg.

Let this list know and if interest is high enough I will post a link to
my site to download it.

Denis