Thanks for the kind comments everyone, appreciated.
Did you experience any particular problems with the Hirst pieces? Any advice to those of us considering taking this project on?
It is a fairly massive undertaking- it takes a lot of time and there is some money involved for molds and such. I used most of a 50lb. bag of Merlin's Magic and several different molds. I enjoy the casting and building process- some people don't and if you're one of those you should step back slowly

If you're up for some casting Roebeast I know you'll like the 'Machinery Builder' and 'Industrial Accessory' molds- I use pieces from those in all sorts of kitbashes. I got those toward the end of building this thing and I wish I'd had them sooner.
I had the casting and building 50% done in the month prior to my son's birth, after that time is my most precious thing and I have to parcel it out in very limited amounts. The LPL and my Wagers of Sin track (using Keebler molds) were big distractions... plus I lived in NYC over the summer so that was two months of 'free time' lost (I teach college and have summer off... that was truly painful to not be able to work on anything).
My biggest bit of advice would be to use a surfactant to spray the molds with before pouring- that was a turning point regarding casting quality. Also, Bruce Hirst had a Space Hulk plan posted on the website- GW made him take it down but I'm certain someone on the boards would have it. I had mine mostly cast and built before Bruce's instructions came out but its pretty much the same, mostly floor tiles with the 'Industrial Edge' mold. Hope this helps, feel free to ask any questions.