Advice on stone staircase- Saintes France

Hi
I have bought a lovely house in Saintes north of Bordeaux- mostly 18C but the stone staircase is probably older in its own tower at the back corner of the house. It is a stone spiral staircase with overlapping steps in shape of sectors of a circle. (escalier en vice)
It has clearly survived centuries but there are someone 5 cracked and damaged steps one of which might be close to falling completely.
Doing some steel girder propping up just in case and limiting use of staircase to essentials!
Not sure how dangerous or safe and need an expert opinion plus options and quotes for repair/replacement. Needs perhaps structural engineer expertise and report with recommendations.
I will be at the property from 12th October and could meet anyone interested in taking a look.
Any advice, contacts or useful information would be welcome.
Thanks
Jean-Marc Michel
I am ok with replies en Français.

vjmichel wrote:

I am ok with replies en Français.


This section is English only but you can post the same thread in the French section.

https://www.expat.com/fr/forum/

I can ask my neighbour if you wish, Barry