flue location on constructed dome

[Toomulla]

Given that the dome is old I would leave it alone, coring a hole large enough for a flue could destroy the old dome , I also do not believe that a flue within the dome will work all that well.
my recommendation would be to either build an entry two brick deep

[Odin]

hi. see my other thread. Oven was in poor condition and I have to change floor and render. SA it was Neapolitan style with upper lip chimney type - I want to make it more traditional oven look with nice round dome and flue in front

[Toomulla]

Why are you not rebuilding what you had

[Odin]

My traditional Naples oven that I am restoring now used to have (before I removed it) upper lip style flue – attached sketch.
While I have removed the lip I have complete dome but with no chimney and entrance. What are your suggestions for installing the flue.
Should I build additional entrance – like 1 brick length and install flue there or try to drill chimney hole just above current entrance?