As for scale..yeah it's actually 25mm instead of 28 so it's not THAT much smaller...besides...if it looks like a GD then it is a GD as long as the size is close I don't see it mattering much...and he comes with a whip and a flaming sword so not much converting would be needed...and I think instead of filing or cutting off the flames, just a lil minor GS work and they could be a really gnarly looking bit of hair...

and as the kit is plastic...the possibilities for converting are pretty much only limited by ones imagination
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I am Wolfpack, my fangs are long, my hair grey with age...I am The Great Wolf...I fight with bolter and Axe, my armies vast, my word final. A true son of Russ, my honor above all, I hunt the heretic, the xenos, and the witch and slay them where they stand! My sons hunt our enemies,
slay them where they falter and bring their pelts to Fenris