Cleaned and stripped part of the Gazelle Lausanne mixte today. Looking a lot better after a good wash.
Also gave me a better look at some of the details on there.
The Shimano STX RC derailleur and shifters needed a bit of adjustment and some WD40 but I think I'll just take them off and replace them with something modern with a bit more range.
I was thinking of building a new set of silver coloured wheels with a dynohub but just outright buying them prebuilt online is cheaper and saves me some time. 36 spokes with Mavic A319 rims should be fine for now.
The end result should look something like this:
Turn it into a 1x9 bike with trigger shifters, add dynamo lights and cream tyres and we will have the basis for a very nice looking commuter bike.
(
Don't mind the saddle. It's adjusted to my height right now. 
)