My granddaughter gave me a book on Scottish hammered coins, "The Coinage of Scotland" by J. D. Robertson, so I thought it was time to add a Scottish coin to the collection. Specimens in good condition tend to be expensive, but this penny of Alexander III with the 26 points reverse came at a reasonable price.
For interest I paired the Scottish Alexander III coin with an Alexander III (The Great) coin. (Same name and both coins feature stars.) The Scottish coin has stars and mullets in the reverse quarters, and the Alexander the Great coin has a star under Alexander's bust and one under Bucephalus. When the Alexander coin was submitted to the RPC it was given it's own page as a new variety. (Now there are two.)
https://rpc.ashmus.ox.ac.uk/coins/7.2/199A
Scotland, Alexander III (1249-1286), Second Coinage, c. 1280-1286, Penny.
Obverse: Crowned bust left, sceptre before. Some ghosting to obverse. Obverse legend: + ALEXANDER DEI GRA. Reverse: Long cross, star/mullet in each angle, total of 26 points. Reverse legend: REX SCOTORVM +. On a full flan.
Class Mb 12h (S.5054). Metal: Silver. Diameter: 19mm. Weight: 1.42gr.
J. D. Robertson's book was published in 1986, but was an unchanged reprint of the 1868 edition. It was almost 150 years out of date, so I looked for information that was more relevant. The British Numismatic Society published a pdf file of the 1990 "Classification of the Single-Cross Sterlings of Alexander III" by B.H.I.H. Stewart and J.J. North. The paper holds a wealth of information on the mints, varieties and mules of this one penny. Running to 29 pages, it is not for the faint of heart in trying to attribute one of these coins.