The date pins #3 down as what Krause calls "Pre-Reform Coinage" of Abdul Mejid. (After a closer look I completely agree with acanthite on that score.)
Size and general appearance-wise, the only match in the 2001 3rd Ed. 19th Century volume is KM#659, 1.58-1.60g of gold (fineness unspecified), with a Qustantiniyah (Constantinople) mint mark. The denomination is given as "Memduhiye Altin", with a nominal value of 20 piastres and an actual value that varied with the price of gold. All dates from 1255-1259 are valued in that edition at $45 VG, $55 F, $75 VF and $150 XF. No mintage figures are given.
The obverse of the copper 5 Para is very similar, but the reverse is quite ornate and totally different. In addition that coin's first year of mintage was Regnal Year 7 (AH1261).
Even though the picture does not look like gold, it would be interesting to know the weight. After all, no one has ever accused Krause of infallibility in it's listings.