First of all - excuse I'm posting here, but I'm not allowed to post at the mocha forum ( odd - relates to longevity of "membership" ??? )
Therefore here:
My first attempt to perform a remove in mocha wasn't that great a succes.
In the footage shown * in the upper player you'll find the original footage. Below there's a modified version that implied
1/ twixtor pro, and
2/ my attempt to remove the footsteps in the snow at the left hand side as seen in the original footage. This was done via a "clean plate"-procedure , illumination model = linear (wow - rendering times!)
Flaring aside - there are still obvious "remnants" of these steps in form of shading ( excuse my insufficient english ) where they originally were placed .... You see a grey belt traversing. Now - in my opinion this is a bit dissapointing - not a tragedy though 
- and I wonder why this occured ? As I see it, the footage is quite homogenous with respect to exposure / white balance and judged as suited for a single screen plate procedure (taken at the last, most relevant frame) but maybe I should've reffered to two clean plates instead of one?
Any other comments / reflections on this would be welcome