The next time someone tells you the large forgeworld kits are tougher than you think to put together...believe them. I've been modeling for 15 years, and this was by far the most intricate and time consuming build I've ever done - but it was worth it!
The Heirophant is now ready for priming - I finished putting all the spikes on (and lost 3 or 4 of them) last night, finished greenstuffing gaps and using liquid greenstuff to smooth out some miscasts, and making sure the leg I had to pin and repair was strong enough to support the body (the vice I was using to hold the model as it dried broke off my desk...and shattered the front right leg).
It does seem strong enough to support itself, although I may use a dremmel to give it a stronger central support in the form of a dowel or coat hanger before spraying. Here are some finished pictures, enjoy:
And here are some close ups of the more significant green stuffing jobs that needed doing, including the broken front leg.