French Bistro Classics - brainstorm help!

Many excellent suggestions herein. What is the date? because the food should mirror the season i think. To keep up your friends' delight and interest, and their feeling of going to FRANCE, I would suggest that you keep to the LESS familiar home-cooking recipes. If you are up for major cooking, you could do a multi-course meal , in which case, you could have a light soup[and dessert at the end], and then a roasted simpler meat, poultry or fish course with a veg. side or two, followed by a small green salad (damn tradition here!) and then a richer stew; and the very best French levain with soft unsalted butter. ingredients that come to mind are: haricots vert; beets; Jerusalem artichokes/sunchokes; celery root; roasted parsnips and root veggies; scallops; john dory; tuna nicoise; cassoulet; rabbit or lamb leg or chop in Dijon wine sauce; pitted prunes cooked in Armagnac and served over vanilla ice cream; crème brulee…. If you did cheeses with drinks, include a non-barnyard chevre; a bleu d'auvergne or forme d'ambert, well ripened buttery camembert, unsalted nuts, and dried fruits. For this kind of French food, I worship at the altar of Paula Woolfert!

There is some contrast between the origins of the bistro (early 20C, mostly owned & operated by people from the landlocked Auvergne region who were internal emigrants to Paris for job opportunities and cooked relatively simple, sturdy dishes from their home region) and its evolution to include similar dishes from other regions (Alsace, Burgundy, Atlantic and Mediterranean seafood). Not sure about the 1970s evolution, but you could make one or two dishes that were popular or becoming more well-known in that decade.
For Auvergne cuisine, including dishes like Lentils du Puy & aligot (mashed potatoes with melted cheese, garlic and maybe sausage) see:
https://www.thegoodlifefrance.com/regional-dishes-of-auvergne/
For popular bistro dishes from other regions, like boeuf bourguignon & duck confit, see:
https://www.gourmettraveller.com.au/recipes/recipe-collections/french-bistro-classics-14831

If you are doing the work and want to enjoy your party, I would keep my menu fairly simple, making dishes that could be prepared mostly in advance. As an aperitif I like to serve foie gras (you can order online from Hudson Valley), a country pate and some jambon de Bayonne with some cornichons with some crusty French bread. French onion soup can be prepped in advance and just popped into the oven to melt the cheese before serving. A cassoulet is another traditional bistro dish. Chicken Basquaise is easy. Mussles (moules) can be prepared a few different ways or you could prepare sole meunière. For dessert you can do a tarte tatin, pot de creme, or a gateau Basque. You could also get some macarons from a local bakery (I love them but don't make them because they are so easy to buy ;) ). Some wine suggestions: For white I like Sancerre and for red I recommend any Bordeaux. You don't have to pay a lot of money for a Bordeaux as they are all good!

Coq au vin