I had one on My Hotrod and sold it to a fellow hammer for around 1,200 bucks I believe complete with working carbs and linkage
I remember seeing an article on one in a 1955 issue of Car Craft so I would imagine that it would only fit a 265 since I had an early Edelbrock three deuce manifold for an early engine and the ports were way too small for my later heads. Never actually seen a Nicson manifold however.