OK, that's now working. Getting MAME to read them natively may be harder.
Code
% samdisk --mx --scale=115 scan work/floppies/A3-05.scp
[work/floppies/A3-05.scp]
80 Cyls 2 Heads:
250Kbps mx, 11 sectors,  256 bytes/sector:
  0.0  0 1 2 3 4 5 6 7 8 9 10
  1.0  0 1 2 3 4 5 6 7 8 9 10
  2.0  0 1 2 3 4 5 6 7 8 9 10
  3.0  0 1 2 3 4 5 6 7 8 9 10
  4.0  0 1 2 3 4 5 6 7 8 9 10
<...>

Will clean up and submit to its github repo soon.