Cherrystone Auctions note: "R.S.F.S.R. Definitives - March 4, 1922, 7,500r blue, horizontal watermark, gutter tete-beche block of four with sheet margin, never hinged and post office fresh, folded twice (vertically) in gutter, just touching two stamps in margin, otherwise v.f. These stamps were printed in large gutter panes and cut along the gutters by the postmasters. They were not sold in philatelic shops and only six tete-beche pairs survive. This is believed to be the only known gutter tete-beche block of four. A fabulous rarity from RSFSR, ex-Shtern (realized $149,500)."