There is a debate whether or not the 109 was in an overall green scheme or one of an overall grey.
In the mid-80s, four of the then surviving crewmen who were aboard her on her last patrol wrote me. Two of the gentlemen indicated that she was in an overall green scheme and the other two gentlemen indicated to me that she was in an overall grey (and one of them said Battleship Grey) scheme.
I am of the school of thought that she was last in an overall scheme of Navy Green with a Copperoyd colored bottom.
Now, you can acquire ACCURATELY matched paint from White Ensign Models in their COLOURCOATS line.
You could use either Navy Green or Tropical Green for everything above the waterline and, even though this color was never used on wooden hulls, their Norfolk 65-A Anti-fouling paint is a very good match for Copperoyd. Or, also, for Copperoyd, you could use rust colored automotive primer paint.
Additionally, recently, one of my colleagues who is QUITE KNOWLEDGABLE about PTs, has informed me, that contrary to the popular belief out there now, that PT boats' shafts and props were indeed bronze in color and were NOT painted over the same color as the bottoms.
Garth
Author of PT Boats In Action and Vosper MTBs In Action
Co-Author of Schnellboot In Action