I just had a go at this and for me there were no problems resizing the model in DR. It may be that your scaled models are in a format that causes the error. For me the format is LWO. If your setting is different, maybe DR is having trouble converting from one format to another.
I also had a go at modifying it in Blender, but it's a difficult one to work with because the canvas is formed of two layers (one facing out, one facing in), but not in a consistent way. And the I'm finding it very had to get smooth shading working, which isn't usually a problem for me.
And yes I know what today is.
Edited by R Soul, 25 December 2018 - 12:21 PM.