First thing I did was go through all th ebricks i have and sort them, I sorted them into "dome" bricks, these are the best ones, straight edges - no chips etc. Next is "wall" bricks, once again straight edges but only needed to be on 1 side and i put the chipped corners to the outside. Lastly "whats left" they will be the chimney, back wall bricks etc.
Here I have placed the dome template on th efloor to make sure the bricks get laid at the correct width, you'll notice the white row on the outside, I opted to not cut any of the floor bricks instead i moved the side brick in and added some hebel on the ouside to support the wall. the main reason i did this is it will be easy to replace the oven floor if it gets worn any time in the future as those bricks are not supporting the wall.
I then moved the template up to ensure it was all straight vertically and rendered the outside of the oven to ensure no gaps
I then removed the template and filled the gaps in any bricks on the inside, I had some mortar left over so i added some chicken wire to the sides and back and pushed more mortar into it, once this dries I'll peel the top chicken wire CAREFULLY back and do my next layers (you can see the 2 bricks sitting ontop of the left wall).This will give me an extra brick height and then the slanted brick to facilitate the angle of the dome, having an angle brick helps reduce the arch angle and the amount of mortar needed to join the bricks.
