[Cob] smoothing wall in preparation for plaster

[Bob Smolen]

I put up my first cob wall. It is infill for a timberframe structure I built.  It is 8 in thick and has dried for a little over 1 week. The surface is very rough because I was rushing to beat rain when I put up the wall. Is it possible to go back with a strawless mixture of cob to smooth over rough spots?
I tried doing a little and am wondering if 1/8 to 1'' "after plaster " (my term)will adhere and be a good base for lime plaster. I appreciate any comments/advice. Next time, I will be a little more careful with the wall surface when the cob is fresh.
Thanks,
Bob