Disklavier

I say Hello to Todd Muncy and all other participants in this group.

Let me express my thanks to Todd for granting me the access and the
possibility to swap (Disklavier) files.
The first thing I have to confess is that I do not own a Disklavier.
Instead I have an Ampico piano from 1923. In addition to play
punched note rolls, I can control the pneumatics also via MIDI.
The MIDI data must follow the same conventions as on a Ampico
note roll; e.g. dynamic is not a property of a single note but
is common to all bass or treble notes. The intensity is controlled
by MIDI commands that are identical to those for playable notes.
So MIDI files for pianos have to be converted by a more or less
intelligent procedure. Looking at the variety of MIDI files on
the net I decided that I should start with MIDI recordings for a 
common instrument. I selected the Disklavier as you can see from
my presence in this group.

Now for some questions: 

1.
Are the files that are stored in the Files Section really
recorded from Disklaviers? Or do they origin from many other
sources and can hopefully be reproduced on a Disklavier?

2.
Who can explain to me the usage of the .url entries in the
file section?

Best regards from warm and rainy Germany

Walter Tenten