mid-50's also works because it makes sense for vanessa to be in her late 40's and still have the 'fisk is older than her' vibe like was it just me or did anyone else get that vibe??
(might be becaue of the actors atually wilson's actor is 55 and vanessa's is 45 although i place the character at closer to 47)

I think part of it is that Elden is like 37 (so older than cox) but just.. idk there's something about they way they interact?? that reads really 'slight age difference' to me. (and i can totally see foggy having had to wait a few years to start college for like... financial reasons or something)
(also as someone else said to me this is great fuel for potential 'foggy going though his midlife crisis' jokes from matt)

I think part of it is the shows ability to have the audience buy into the image Fisk had been trying to create for most of the series, which is really impressive in my mind. Fisk has a real presence to him that makes me feel nervous, like he could actually affect my life personally (also just, specifically the flashbacks. holy shit that's some bullshit to go though :( )