Quite a while ago I came across this document on how to process sashimi grade tuna. I don't know who wrote it but am offering it up for those who are contemplating processing their tuna catch into sashimi grade tuna. If you are the owner of this document I am happy to attribute it to you. For some reason the author is not mentioned in the article.
How to Process Sashimi Grade Tuna - sashimi.pdf