Identity by Ordered Subtraction

A number N consists of unique (all different) digits. Let A be the number formed by putting the digits in descending order. Let B be the number formed by putting the digits in ascending order. Find all possible N which satisfy A-B=N. (Leading zeros are allowed, if needed.)

Are there any additional answers if we remove the requirement that N consists of unique digits (but still be no more than 10 digits)?

Source: Based on a problem from Casio's Problem of the Week. Original extensions.

Solutions were received from Al Zimmermann, Denis Borris, and Philippe Fondanaiche. Philippe pointed out that from the initial non-repeating solutions, we can infer a limitless number of other, repeating solutions. You can see the pattern in the list below. Denis listed the solutions through 13 digits: 
(R = some digits Repeated)
DIGITS              A               B                N
   3              954             459              495
   4             7641            1467             6174
   6R          995544          445599           549945
   6R          766431          134667           631764
   8R        76664331        13346667         63317664
   8         98754210        01245789         97508421
   9        987654321       123456789        864197532
   9R       999555444       444555999        554999445
  10R      7666643331      1333466667       6333176664
  10       9876543210      0123456789       9753086421
  10R      9987542100      0012457899       9975084201
  11R     98766543321     12334566789      86431976532
  12R    766666433331    133334666667     633331766664
  12R    987665433210    012334566789     975330866421
  12R    998765432100    001234567899     997530864201
  12R    999875421000    000124578999     999750842001
  12R    999955554444    444455559999     555499994445
  13R   9876665433321   1233345666789    8643319766532
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