Hi gsarroni,
sorry but I cannot help you with this! But your post reminded me of the discussion we has not so long ago when I had been considering buying the DW-6. Having read everyones comments I decided that it was not really for me and that it would end up on the shelf along with all my other unused equipment. Then I too found an image that just would not fit into the 24mm field of view of the GX100 and so took the plunge and bought one (new...cost me the earth on a German website... because I wanted it in a hurry...)
I figured though that it is likely that I will buy a GRDIII sometime in the future and as the DW-6 also fits it that model, it really is two for the price of one...
Oh well, sorry about this unhelpful post... :?
Hope you find one soon!
Andy