Believe I saw this piece on
ebay recently. Don't think I had ever seen it before (Bob?), but simply from observation/experience (let alone the "fabric" of the physical stamp itself), it's almost certainly a modern concoction (fake stamp). Numerous fabricated Islamic-world stamps of this general style have surfaced on 8 Reales (and others such as circulated Maria Theresa restrikes) over the past decade.