Recommendations please for close-to-wall book-shel

I would suggest a front ported speaker or a sealed cabinet. Stay away from rear ports.

Linn Tukans go close to the wall, and may make it down to 55. Might be more like 60. Not very expensive ($350).

Von Schweikert VR-1s. I have them in a 12" deep bookshelf (not my idea, a compromise with the spouse) and the imaging and width of the soundscape is wonderful. There is a small "port" on the back described by Von Schweikert as pressure relief. It doesn't act as a port. I am very happy with them. $999.

Soliloquy SAt 5 should fit the bill. I use 2 for surrounds in my HT, but they are actually decent as mains suprisingly.