Spent an inordinate amount of time carving up plastic yesterday, and managed to make a fair bit of progress on the composition front too. On the scraping front I remove a large chunk from the terminator torso so that the Nurgle "brooch" would fit flush(er) with the armour rather than just sit on top and stick out like a sore thumb. The knives got scraped off the belt, and the cloth got "nurgled" a bit (though more progress is needed there). I also had to chop up the original Spume model in order to fit the termi torso in. Most notably I cut the shoulder and the brooch away from the front or the torso and remove the original left hand side and neck of the model, reattaching the tentacle afterwards - there's no going back now
In regards to composition, I decided on the mace from the
DW kit to replace the original model's axe. I also picked out a terminator arm from my bits box at random just to see how it would look. Turned out to be the
GK one with "death" engraved on the elbow. How fitting

So I cut off its shoulder (though it needs trimming down further). Finally while rummaging around in my bits box I came across the cloak from the
CSM termi lord kit and think it works amazingly on the model. The little exhausts that piece have will also help to
40k-ify him a little more.
Anyway, here's how he stands
atm all blu tacked up (god I wish there was something that held better than blu tack):
That last image shows where I'll be putting the little maw that usually goes on the Gutrot's left side. It should help close the gap between the termi torso and the energy pack that's a part of the cloak piece. There are a LOT of gaps that will need filling
Edit: forgot to mention, I'm having trouble working out what to do with the terminator torso's belt piece as it's well of centre for this model. Don't see an immediate fix so any ideas would be much appreciated.
Feedback always welcome, let me know what you think!