Here's an interesting casting idea that I had for Kingpin....how about Kelsey Grammer? Hear me out....he may be a bit thin, but frankly, people who want a living personification of Wilson Fisk are just deluding themselves. You just are not going to find a viable actor who is in his mid to late 50s (or even 40s), who is also 6'6 and 300 lbs of pure muscle. It won't happen.
Plus Kingpin's physicality is not even his defining trait. Sure, physical intimidation is part of it, but it isn't what defines him. Tony Soprano could be physically intimidating when need be and he was short and flabby. You don't have to be a body builder to be physically intimidating. Kelsey Grammer could put on 30 pounds and a few prosthetics and look just fine in the role.
More importantly than looks however, he would nail it from an acting perspective. I don't know who watches the recently cancelled show Boss, but Grammer's portrayal of Tom Kane (mayor of Chicago) is essentially Wilson Fisk. Here's a censored clip:
Look at the power he exudes as he dresses down the governor of Illinois. It is exactly the type of power that Fisk ought to just radiate. Very few actors can simply exude power through their presence, Grammer is one of them. Plus, the resemblance isn't that far off if Grammer were to put on a little weight.
Say it with me, Kelsey Grammer for Kingpin!