I'd say 1970 to 1973. It has a red seat, which didn't come around until 1969, and the slimmer bars, which started in 1970. If you had a picture with the shifter or the pedals I could pin it down a little more.
The bike to the right looks to perhaps be a Cinelli Vigorelli, no slouch of an aluminum track bike from the late aughts, early 10s.
The bike to the far left looks to be another fixie of some flavor. With the board, track bikes and Fastback? I'd be falling over myself to get to this storage shed sale!
Red Deluxe seat was indeed an accessory. This bike is a J-39 model more than likely came out of the box with a silver glo and no fenders. At some point the seat was changed, possibly a dealer or customer upgrade.