ORIGINAL: CK1
It looks a little rich on the high end ,but not excessively .
The spattering on the plug looks like maybe too much oil in mix , what oil and ratio are you using and what octane fuel and how old is it?
The oil I am using is Motul 800 40:1, if I am not mistaken, the Octane of this gas is 87.
The oil traces in the LG and fuselage might indicate that I might be in the reach end. should I try 50:1?
However the spark plug indication is saying that I might be Ok , as you said it is not excessively reach.