Sorry, my knowledge of German is insufficient to answer in this language.
In februari 2013 i downloaded a very basic version of Velesovo for GO :
Made with Organ Definition File Creator (c) 2013 by Wolfgang Schneider, http://grandorgue.seeyoo.net
I cannot find a trace of the author nor of his conversion program.
Unfortunately this website seems no longer to show anything but the home page.
At the time his program was not yet finished and the resulting conversion therefore incomplete.
The stops are there and working, but no swell pedal, couplers or other playing aids are available.
I cleaned the ODF so that when loading in the latest GO version (1309) no error messages pop up.
Maybe the attached file is a starting point for somebody.
All the best.
Erik.
P.S.
I agree with Michael that using the wet version of the Velesovo set in GO with reverb set to max, but even with reduced reverb length does not sound very realistic. In Hauptwerk in contrast i like it a lot.
[navy]< I´m sorry - this Attachement was deleted by the Admin, because the Copyright for this ODF is still by the owner and so it is not allowed to distribute it here ! >[/navy]