Recently I have purchased a few Egyptian Zeri Mahbub (18th century hammered gold coins) in Unc grades and also a large number of Ottoman 16th-18th century silver coins from some hoards (all small, thin,hammered coins). All these coins were pierced long ago.
Does anyone know the difference in value for these coins compared to similar but unpierced Ottoman coins? The standard catalogues don't seem to mention the drop in value attached to pierced coins (or the premium for unpierced coins when most coins were pierced).
What is the best way to conservatively clean the hoard coins? They are coated/encrusted with centuries of dirt but look to be of average to decent grades.
BTW is Uslu the best website for Ottoman coins and are his catalogues worth buying (or is there some better books for looking up Ottoman and especially Egyptian coins).
Advice welcome, TIA