Ottoman regnal dates inconsistencies [solved]

There appear to be inconsistencies in the way Ottoman regnal dates are converted into AD dates. For example, take these two Egyptian coins:

https://en.numista.com/catalogue/pieces69701.html

https://en.numista.com/catalogue/pieces36884.html

In the first, year 23 of Abdulmecid I (1277 AH) is converted into 1860 whereas, in the second, the same year is converted into 1861. It seems that the conversion for the first is based on the AD year the AH year began, resulting in both years 7 and 8 (1261 and 1262 AH) being listed as 1845, wheras the second does not allow for this, possibly following the rule that the conversion is based upon the AD year in which the majority of the AH year occurs (the next "rollover" being in 1862).
For the first coin, the regnal year is given in the comment for each coin whilst, in the second, the regnal year is given as a mint letter with 1255 in the comment for each year. Consequently, it appears that the conversions to AD are automated. If that's the case, is there a guide somewhere as to how to set these dates up and what convention to follow?