Well that's nice. Eighth AF B-17 gets eaten by the English. Great headline! The poop is a new idea for weathering.
I had an an English Springer that did the same thing. Something seems to be going on with English dogs eating plastic? Down one each Monogram F-106 (I refuse to call a Monogram a Revell).
All kidding aside I'd look at Terry's input. Go up online to Revell.com and you may have to go to Revell Germany and look for replacement parts section.