Very Nice, I have a similar build but it is an over under cement pit. One thing, I learned from experience, is that your oven looks greatly insulated underneath, ( I like those bottles ! ) but as you know everything that counts is up above. I had to keep adding tricks to get enough insulation above the pit. My last trick which I really like, was to add the perlite, thermorock to the mortar on the dome. They sell it at home depot a large bag very cheap. It really helps insulate, its like mini volcanic light rocks. You mix it with the mortar / clay and it really insulates. I read about it here somewhere and if you can still add it I recommend it. It can be on the outer or middle layer, doesn't matter.
" Don't ask me who I am " CENTRIXS