Maybe someone can help: My Tele-Xenar Compound does not work any more in T and B mode. That is because the shutter blades stay open instead of returning to their normal position, which is shut. I made a careful inspection of the mechanism and I can see no spring whatsoever that I think, should be here to force the rotating mechanism to return to it's place when it is released from the "open" position. With other speeds, the mechanism is actioned by a cam and it works fine. Before considering an expensive two ways overseas shipping to SK Grimes Associates, for a lens I hardly use, could there be someone who could confirm my diagnosis? Thanks!