Finally found the photographer.
Vintage original Official RCA "Lodger" promotional 8" x 10" b/w still by Brian Duffy. Printed on double weight glossy stock. Signed with steel tipped pen in blue ink. Dedication with inscription. 10/10 Mint. Optimal contrast and placement, signed with blue steel tipped pen. Of the 1977-1980 SP's I have seen, this seems to be among the best. Many are signed in black on black. The only way this could be better is if he was holding a microphone as far as I am concerned. But, this is Berlin.
BTW, those few scattered marks in the "Bowie" are in the photographic finish - they are the same color as his coat and all and show no difference in gloss when viewed with a glass. Thus, I do not hold this against the condition. Do you? This is a first gen photo. I agree an example w/o these marks would bring more $, but I do not know if they all have these marks. As part of the creative process, I do not hold these marks against the condition.