If you open an RPP-file in a text editor it should look something like:
Code:
<REAPER_PROJECT 0.1 "4.25"
RIPPLE 0
GROUPOVERRIDE 0 0 0
AUTOXFADE 1
ENVATTACH 1
MIXERUIFLAGS 11 112
PEAKGAIN 1.00000000000000
FEEDBACK 0
PANLAW 1.00000000000000
...
The files you link to look nothing like that, they seem to be binary files of unknown format. So sorry, there is nothing to salvage here.