Thank you for the information. I have come across this interesting bit of information from papercoinage:
Notes on Octavos and Quartos
Octavos and Quartos minted from 1771 through 1835 include many die varieties, most of them too minor to have been noted in detail by numismatists. No official mint was in operation in Manila at this time. Manufacture of these subsidiary coins was assigned to private Chinese contractors with little technical background and, it would appear, even less knowledge of western alphabets. Their coins were so crudely struck that to a casual observer they almost appear to be counterfeits. Errors, such as inverted letters, abound.
Many of the quartos were struck so weakly that the dates do not appear. The wear from subsequent circulation, of course, helped contribute to this defect, but Gilbert Perez has described the discovery of a hoard of some 80 pieces of the 1828-1830 type. All the coins were in mint condition with full luster, but most of them lacked dates.