Well I had some luck in learning how to extract specific parts of an image file, in this case individual decals. I found another great image manipulation program called
Paint.NET . It is similar to GIMP but the interface seems a little more intuitive. I also found a number of good video tutorials for Paint.NET available on YouTube.
So I followed one of the tutorials I found for cutting out the background from an image. Unfortunately, there still seems to be some glitches in applying textures in the latest version of Rocksim. I applied the attached graphic to a fin of one of my designs. Only the lettering appeared on the fin, not the white background. I also tried to utilize the "rotate around R" and "rotate around S" axis options and found that it changed the physical shape of the fin, not just placement of the texture.
To confirm this problem, I opened up the Estes Orbital Transport design file supplied with Rocksim v9 and heavily uses the texture feature. If you go to one of the rudder fins and select option to rotate around s or r axis, the shape of the fin changes.
Well another item to add to my list of Rocksim v9 anomalies. I'm going to email these items to Tim and Paul at Apogee so they can add them to their bug tracking process. I think they are already aware of some of them.
... Bill