Forrest, thank you for posting about your FGM build!
I have a keen interest in your thread as I have a FGM 950C sitting in a crate in my garage, waiting for it to get warmer before I start my build. Love the look of your 950B and don't know why I didn't order that version, but "C'est la vie." (That's for you Antoine...

) BTW, I'd like to add that Antoine was wonderful to work with when ordering my oven!
I hope you don't mind if I ask a few questions, perhaps it will help others as well...so here goes.
1) I noticed you used sand to level the floor tiles. I had read this wasn't necessary anymore as the oven floor had been improved. I assume you found it necessary. Does standard "play" sand work, or did you need to use something else?
2) I'm planning on an 8" chimney. The included flue adapter in my order is supposedly 200mm which is slightly less than 8". How did you connect your chimney pipe to your flue adapter, any "adapting" required?
3) I've read that one of the advantages to tiles is if you break one, you can easily pull that tile out and replace it. However, the perimeter tiles are installed with refractory mortar/clay on the outer edge. Is that because the tiles would move too much without anchoring the perimeter? Would you be able to replace a perimeter tile if necessary?
4) Lastly, I'm curious about the small gap between the tiles. Is the gap large enough that "junk" can fall in between the tiles. If so, would it just burn off, or is it so small that it is a non-issue?
Thanks again for a very informative thread and I can't wait to see your first pizzas!
BTW, I'm very excited that I get to meet Antonio Starita, Roberto Caporuscio, and Antimo Caputo at "Marcos Coal-Fired Pizzeria" in Denver this Thursday evening! I promise to share any tips I learn!
Bob