You might consider choosing a brick color from your fireplace and redoing the floor in faux brick look tile.

DIY brick tile floor:

https://thekellyhomestead.com/2018/01/24/foyer-accent-floor-chicago-south-side-porcelain-brick-tile/

Why are you excluding Marmoleum? It would be perfect for the age of your home, and most certainly comes in the retro designs you said you want.

Because they started to put in hardwood floors in that era. you should.!!! Fairly open / nice fireplace / and ceiling. Basic hardwood on floor would be best upgrade. You could probably DIY

Is that cork??? Or is it terrazzo?

I suggest hardwoods for the living room, and super basic linoleum tiles for the kitchen. they're inexpensive! choose one color so it doesn't look crazy, and alternate the direction of the pattern. like below, but not black.

I really love your house! those original details, so cool.

If that were real terrazzo in the living room, I’d tell you to leave it, but you are indicating that it is lino, right? This was very nicely done, you have a 3/4” plywood beneath that surface that allows the floor to be level with your hardwood. Vinyl would be a step down in terms of quality. Linoleum means marmoleum now, and I agree you should consider it, but I like @herbflavor’s recommendation. Continue hardwood flooring into both rooms. It will look great, wear beautifully, and visually, it will connect your rooms seamlessly.

Thanks everyone! The rest of the house has nice oak floors. I love the original linoleum (faux Terrazzo) but it’s damaged in some areas. we wanted Marmoluem in “chocolate blues” but it doesn’t come in the click, so I’m trying to find some other options. I want to keep the flooring the same in the dining room and kitchen since they’re open, so wood isn’t really an option (also cost). We may just go vinyl in the end

Cork floating floor in the same optics as linoleum (aka Marmoleum = brand name linoleum).

https://www.icorkfloor.com/store/cork-floor-planks-walnut-burlwood-12mm/

The price is $3.40/sf. Installation = identical to floating marmoleum.

Did you know marmoleum has 'up keep'? As in applying a polish every 4-6 months for the rest of it's life? Right. Best to know that before hand.

i have definitely seen vinyl tile (and sheet) designed for just such a purpose. Can't remember where just now...

How about slate? There are lots of examples of midcentury slate done in colors or solids, usually in a Mondrian type pattern. Not in kitchens, maybe, but you can fudge authenticity a bit.

Some slates are too flaky or porous for a kitchen, but some are totally fine. Cheap, too. :) I have had unsealed slate in my kitchen, family room, laundry, and powder room for a few years and we are absolute slobs. No stains. I used this in 3 sizes. So cheap. Still love it. https://www.bedrosians.com/en/product/detail/country-grey-tile/?itemNo=SLTCOUGRY1616B

(I love Marmoleum, but it didn't work in my current kitchen.)

ETA: I had Marmoleum for years. No upkeep. Polish is optional. I opted not.

These tips and ideas are great! The kitchen does need a lot of work. The fluorescent lighting is atrocious, and the entire house had awful white carpet that I tore out to reveal nice oak. We’re replacing the appliances and pulling out the shelving above the counter. I kind of love the avocado Formica counters but they’re damaged in a couple spots so will need to be replaced soon. Flooring is tough because the fireplace is in the dining room! I’d love terrazzo or stone, but those aren’t in the budget (and might look a little over-the-top for the modest house). While I love the look of cork, I don’t think it’s tough enough to withstand kids and pets and liquids in a high-traffic kitchen/dining area. I’m leaning toward a retro vinyl print I found that is about as close to the terrazzo-print Lino we have now. These are the options I'm considering: first two are bold colors in vinyl tile, third is a safer faux terrazzo kind of look in sheet vinyl. Thoughts?

I just saw that Armstrong is bringing back what looks like your pattern in 4 color ways.

Armstrong brings back the pattern!

I love the teal vinyl tile! that color will look gorgeous with those wood cabinets, and maybe off-white counters.

sorry but I strongly vote no for the last two options. the denim blue seems too "kid's room" to me. the grey is so high contrast, it reminds me of the kinds of busy granite counters everybody wants to rip out these days. seeing a whole room of it might be a lot.

whatever way you lean: can you order a box and return it if you don't like it? that way you can lay out a big area and really be sure of your choice.

I love your avocado counters too! if you wanted, a part of them could be cut and repurposed in the laundry room, garage, etc.

I just had marmoleum sheet installed in my mcm flw kitchen and i love it ! Installer said maint was cleaning as normal - we went with their new concrete line

Deb if you’d be willing to post a pic I’d love to see how it looks

@Taryn here you go

Vinyl was not typical in the 50's but as mentioned cork flooring and terrazzo would have been used.

https://www.ghsproducts.com/

https://www.tileoutlets.com/blog/whats-new-in-tile-terrazzo-looks-at-cevisama-2018/

I LOVE that aqua! But then again, this was my kitchen:

https://www.houzz.com/discussions/2873984/here-s-as-close-to-a-reveal-as-i-may-ever-get

the terrazo Beverly posted would be perfect, I think, but I believe the budget might be too tight for it. the various linoleum products OP listed above would give a similar look.

crcollins1_gw OMG cute kitchen, I'm obsessed!

Deb it’s so pretty! The sheet marmoleum looks so sleek and I love that color with the cabinets