As to the bb overhaul, I hope that you find pristine bearing races inside! Those 118mm Stronglight spindles are a somewhat precious item.

I don't remove the fixed cup normally, the factory put them in good and tight from all that I have seen over the years and the 8-sided flats are narrow enough to cause normal wrenches to gouge and slip off unless measures are taken to really affix the wrench onto the cup as quite-heavy torque is applied.

I did come up with a solution for removing and installing these octagonal Stronglight cups in the form of a 12-point socket and breaker bar as illustrated below.
It is by sheer luck that this 12-point, 1-1/2" (or 38.1mm) size fits snugly enough on the 8-point fixed cup points. I tried the very-next-smaller 1-7/16" size as well and it did not fit, so this seems like the best we can do using inexpensive, ordinary tools. Note that sockets like this aren't that cheap unless you buy off Ebay or get them at the thrift/pawn stores like I did, plus you'll need a breaker bar or hefty ratchet to use them. I prefer the flex-handled breaker bar because the handle can be swung into the exact plane of the socket's engagement such that there will be zero off-axis torque trying to tilt the socket off of the cup!

This almost 60-year-old bb cup came right out using the tool pictured.