I haven’t tried the skales tools with 3.10 android kernel. they might not work… the tools were designed to be used with recent/mainline kernel. it is possible that the 3.10 DTS files do not contain enough information for dtbtool to work properly.
maybe someone can investigate further… or you can have a look at the Android build system (from Android CAF manifest) to understand how they build their boot image, they don’t use skales.
btw, your issue is not related to fdtget.