Hey Upnorth,
Here's some links to sites about the B-29/Washington. Washingtons were, indeed, ex-USAAF B-29's loaned to the RAF (Almost 90 aircraft, Including at least four RB-29 recce/ELINT birds) and the RAAF (2 aircraft).
Most of these have no photo reference, and those that do are mostly poor shots, but I hope this helps some.
http://www.csd.uwo.ca/~pettypi/elevon/baugher_us/b029i.html
http://www.raf-waddington.com/specials/museum/b29/b29.htm
http://users.chariot.net.au/~theburfs/washingtonMAIN.html
http://www.raafmuseum.com.au/research/aircraft/a2series/wash.htm
http://www.spyflight.co.uk/RB29.HTM
http://www.rafwatton.info/subjs/wash/wash1.html
http://www.uswarplanes.net/b29.htm
Fade to Black...