I have a Foodsaver and know my way around fish, but thanks for the input. That first pic was taken as the freshly butchered tuna was being bagged and sorted (I was about half way through in that shot). Some of what you see was subsequently frozen. Unfortunately, non-blast freezer frozen tuna will change color on you before too long, and IMO the quality diminishes. Which is why I eat so much and give more away fresh.
As far as some sushi suggestions, I have lots.

First thing is to understand that with the quality of fish we have now, the cuts are most important, both in terms of what part of the fish, and *how* the flesh is cut. I've seen a lot ruined by noobns doing things like cutting with the grain. Big no-no. Also, if making maki or nigiri, the quality of the nori (seaweed) and rice is almost as important as the fish. Most nori sold here is far past its best (stale) I've learned, and while it will work, using so-called 'sushi rice' is a good start, but the proper cooling of the rice and addition of sushizu (quality sushi rice wine vinegar--or sushi no ko) is just as important. It's comparable to serving a great burger on a hard, stale bun with withered lettuce. More later on that if you like, but thanks for the comments.
KG