SWAZILAND SG145w 1968 Independence 2 1/2c variety WMK INVERTED U/M Block

1968 Independence 2 1/2c black and vermilion type 42 opt variety WMK INVERTED lower right corner block of 4 unmounted o.g. One stamp with minor wrinkle still attractive and scarce in this positional form. Purchased from Stanley Gibbons (still on their card)