Hello,
Hmmm
1/ Marc wrote RT+.U? (dot for missing letter), not RT+U?
2/ Given the the black triangle behind man's shoulder doesn't seem to be another U but an X, a V or, eventually, a T.
I did start a thread about this one, month ago, in TOCH (doesn't mean I know and doesn't mean I did find something more) ... But I'm still thinking that White 27 style on cowling points to a Finland AF plane.
A G-8? No way, whatever. I think there is too much "full-complete-stkz-batch" in Bert site. And only one - if ever confirmed - doesn't mean the serie is complete.
But, of course, I can be wrong

.
Cheers, Franck.