SG 217 1/2d Pale Yellow Green M2 (-) assumed booklet pane MB1a (no booklet selvedge of course to fully confirm) though with inverted watermark we can be near certain. Here in generally fine and fresh unmounted mint condition with just couple of pin prick tone spots to reverse most would overlook and subtle rather than aggressively trimmed perfs.

Most of course get broken up and sold as singles now with such high demand for this watermark variety.