Hot crab dip, anything involving jell-o (shots totally count)... Pigs in blankets seems to be an evergreen--and they get gobbled up whether or not you're being ironic. For authenticity, go with the Pillsbury bread-in-a-can and cocktail weenies. (Ech.)

For something less authentic and a LITTLE classier (but not much) use puff pastry and actual sausage meat--remove the casings and run a line of sausage meat down a long thin piece of pastry. Roll it up, chill it down, slice it in little rounds, glaze with egg yolk, and bake off in a hot oven (~400) for a good 15-20 min.

If you are a New York Times Subscriber, you can search recipes by date range. I selected 1/1/1950 to 12/31/1959 and got a bunch of hits. One interesting recipe is Eisenhower's beef stew from the 9/28/54 NYT.

there was a top chef masters episode about mad men era food recently that should be relatively inspiring: http://www.bravotv.com/top-chef-masters/season-3/everything-old-is-new-again

I think you could do a lot simply with the presentation... use vintage plates, napkins, glasses, and it won't really matter what the actual food is. :)

I would definitely take a look at Mastering the Art of French cooking - not that it's dated, but it would give some charming, classic options too

Beef Wellington is nice old-fashioned dish. So is Chicken a la King and anything in aspic. And Bananas Foster and Baked Alaska for deserts.

I have a collection of 1950s cookbooks. They are relatively easy to find at thrift stores and used bookstores, and they are nearly always cheap.

Oh, you HAVE to see the Gallery of Regrettable Food...

http://www.lileks.com/institute/gallery/

I'd go for Swedish meatballs in a chafing dish.

I had a casual wedding but wanted nice champagne and real champagne glasses, so I scoured thrift stores and managed to find about 75 beautiful champagne glasses, each for under $1 (cheaper than renting). Many were vintage-looking, the shallow kind. It made for a very pretty table at our wedding!

For food, how about mini burgers/sliders? When I think of the 50's I think of the first fast food, diners, sock hops, etc.

I hope the wedding cake is covered in sea-foam green frosting and dappled with those little silver balls (which are, apparently, inedible).

Another thing to pick up at the thrift store: vintage serving bowls (Pete Campbell: "It's a chip-and-dip.")

This thread on mad Men menu has some good suggestions - for example, celery slices with pimiento cheese, some kind of punch with ice cream in it, nut-studded cheese log, cheese fondue, chips and French onion dip, pineapple upside down cake.

I threw a retro cocktail party a couple year ago that featured an extensive retro menu. I detailed it here in this post; you might get some ideas from it! Some of the most successful dishes where the molded salmon mousse, the baked ham, the deviled eggs, the rumaki, and the cheeseball. Oh and people LOVED the swedish meatballs. If you start with good ingredients and make things from scratch, you can turn some of those scary midcentury foods into fine dining. http://www.alwaysorderdessert.com/2009/12/1960s-cocktail-party.html

Feel free to email me if you have any questions about any of the recipes or want more ideas. My email is on my site.

brini maxwell has some fun vintage recipes and ideas on her website/blog/podcast thing.

http://brinimaxwell.libsyn.com/

@alejandraramos - that party looks great! bookmarking your site now...

I definitely think of diners, mini burgers and cute paper cones of french fries. A big punch bowl, pigs in a blanket, soft serve ice cream cones, deviled eggs... presentation and quality can dress them up. Or 'fancy' tv dinners, you can present them in their compartments but have delicious food :) Rootbeer floats and milkshakes... but I knew there must be more so I googled it and this site might help alot :)
http://www.foodtimeline.org/fooddecades.html

Crab Dip, Stuffed Mushrooms, Stuffed and baked Clams and Shrimp Cocktail all fit the bill.

There's a SF restaurant with a similiar era theme, perhaps their menu might yield some ideas:
http://www.thermidorsf.com/menu/thermidor-dinner-menu.pdf

@kittykatofdoom -- I was thinking the same thing.

Last year one of my friends served mini beef-wellingtons at her wedding receptions...sooooo good!! But I love beef wellington in general and pretty much anything wrapped in puff pastry.

You might also want to check Gourmet's archives if you can.

Chicken Divan - A classic and it's pure heaven

Lots of people have mentioned good stuff, but I'd go for the classics that still get eaten up: deviled eggs (but you could make yours more modern with additions like capers, wasabi, caviar); stuffed mushrooms; upscale canapes (like smoked salmon); and you can never go wrong with classy pimento cheese (sub in white cheddar and roasted red peppers); and if you're really going for it budget-wise, a raw bar with oysters!

Rumaki!

Oh, lotusmoss: no proper Southerner would ever eat a perfectly good deviled egg that had been ruint with that fancy stuff! Why mess with perfection?

Take the 50s classics and modernise them - bit-sized salmon mousse served on mini toasts; corination chicken with mango in it - that kind of thing. Use the popular themes of the 50s, but adapt to reflect current tastes.

Stuffed mushrooms!

@Jezebella -- Agreed!!