Having found the OSR Group on OGS, I noted that there are some Ladders operational. Would it be worthwhile considering setting up the DDK ( and/or othrers ) League there too so that OGS players could identify potential opponents? It may be that this is already covered as I am very unfamiliar with just how you invite a particular player to a game on OGS

Hi Mercian,

I am not that familiar with OGS neither but to invite a player to play, you click his name and click send challenge button. You can use the searchbox on the left to find a player.

The OGS ladder are for correspondence games only I think. OSR team is not involve in those at the moment. You are very free to join them and have fun with other OSR player though. You should find specific OGS ladder rules here.