I discovered a second Lithuanian R-L21* today as I was looking through the Jewish R1b Project (kit 2831):
The ancestral surname is Lubatinsky, from Kudirkos Naumiestis, Lithuania. I have emailed him and invited him to join the R-L21 Project.
I hope more Eastern European R1b1b2s will order the Deep Clade-R test.
By the way, his closest match in YSearch is Prager, our other Lithuanian R-L21* of Ashkenazi heritage (35/40). No one else is close at all, except at 25 markers, where there are a couple of other Ashkenazi Eastern Europeans (Marcus and Millstein) and a Dane (Peterson) at 2 and 3 away.