Next picture shows the little darlings stuck in place at the crucial corner and lower edge of the kento-board. This pushes the block and therefore the image AWAY from the kento.
And the block flush against the adjusting tape.
If the adjustment requires that the image or color block be moved TOWARD the kento, or "pa ca" or "over here" or "inwards", I just shave the block with a straight chisel, one millimeter at a time until I achieve registration.
Although this seems like a permanent non-reversible fix, if I shave too much...well, there's always more tape!!!