Hi!10xloupe:KD#003 and Guj.S#086 are very rare and the other Khandesh coins are rare as Goron and Goenka rates them.
I catalog my coins using a system I find convenient.I first identify their category and then give an ID number with two components. One of them is its category code and the other is serial number. For example, Khandesh category is denoted by KD and Gujarat Sultan as Guj.S. A hash separates the two components of the ID. Numbering the coin is after arranging the available coins chronologically. ID number is serially given with the category code prefixed . If there are five coins of the first ruler, numbers 001 to 005 will be his coins. The next ruler's issue will start with 006. Thus coins of the first ruler of Gujarat Sultan will bear ID from Guj.S#001 to Guj.S#005 or to whatever number of coins are there. The second ruler's coins will begin with the next number.
If there is an addition of coins later, they can be interposed with suffixes like "a" "b" "c" like that. Coin holder will show the ID number of the coin for reference. Thus an additional coin of the first ruler of Gujarat that is to be interposed after the second coin will bear an ID Guj.S#002(a).
At times, coins once misidentified and later on properly identified make a confusion. I shift the coin but do not change the coin ID. That is how Khandesh coins bear two prefixes like KD and Guj.S.
Previously I used to number the late additions with numbers following the last serial number of the category. This gave me some trouble and so now I follow what I wrote above.
Thank you for being with me here.