The following coins of Arados were struck between 115-113 B.C (era date 145-146) and belong to série 7, 8 & 10. For those of you acquainted with the Phoenician alphabet and in particularly that of Arados, the letters highlighted in the image below will appear extremely unusual (No.1-4). Coins struck two years prior and after show no signs of irregularities, as a reference i have added two samples of these coins to the image below (No.5-6) . If we begin with the highlighted letters on coins 1 to 4, at first glance they seem to resemble beth & nun but mirror imaged. I suppose one could possibly categorise these letters has being blundered, but perhaps there is a more logical explanation for this oddity . After checking reference books and the coins in my collection for similar formed letters, no coins struck before or after the aforementioned dates were found. I then began to think along the lines of travelling engraver, someone specifically brought in to produce dies for the three series mentioned above . This idea prompted me to look further afield and so i started comparing the Sidonian and Tyrian alphabets.
Highlighted letter right, nun ?
After many hours of studying the numerous varieties of lettering, i found one version of the Sidonian letter nun which was almost identical but written with the usual rotation. The second was the Tyrian letter sadhe, also extremely similar with a rotation closely matching that of coins 1-4.
Highlighted letter left, beth  ?
Towards the end of G.Hills introduction to BMC Phoenicia are the alphabets of all the major Phoenician cities, listed under the city of Tyre is a mirror imaged letter resh .
On certain bronze issues of Sidon there is a version of samekh that should also be considered as a possibility.
On page 69 of Duyrat 2005 (Arados Hellénistique), the author of the book understandably questioned both of these disputed letters but could not decipher their meaning .
Series 7,8 & 10 in Duyrat 2005 are numbered as follows;
série 7 – No.2447-2455 / série 8 – No.2542-2543 / série 10 – No.4383-4386.
In my opinion the chances of blundered lettering occurring on all three series over a period of two years is highly unlikely, unless it was intentional and included as part of a makers/engravers mark.
I feel these coins will inevitably remain a mystery but hopefully in the not too distant future, i will have the opportunity to study the BNF coins in hand at the Paris Museum.
For the purposes of attribution, i have opted for the following combination of letters, mem, yodh, taw & sadhe. I made this decision purely on gut feeling and for want of a better solution.
 No other issues spanning the Persian or Hellenistic period of Arados have similar letters on them.
 If the letters were blundered, why didn´t the city leaders stop the production of coins after era date 145 coins were issued ?
 Possibly someone from the Aradian dependences or elsewhere in Phoenicia.
 We can almost certainly discount a blundered or mirror imaged beth, below the era date on coin 3 is a perfectly formed letter beth in combination with the disputed letter.
 I feel this option needs to be overlooked, see tail of disputed letter on coins 1-4.
 The letters reference in Duyrat 2005; M, Y, N?, S[ts]? or mem, yodh, nun & sadhe.
I would like to thank BNF for allowing me the use of their images for coins 1, 2, 3, 5 & 6.
Listed below are the 10 known samples of série 7 with disputed letters.
Arados 115-113 B.C (145/146), dans le champ droit : B ; à l’exergue : M, Y, T ?, TS ?
1. 2447 D82-R154, collection A. Ronde, Paris. 18,1 mm.
2. 2448 D82-R155, Berlin. 3,47 g, 18,6 mm.
3. 2449 D82-R156, New York, ANS 1944 100 70661 Newell. 4,30 g, 18,0 mm.
4. 2450 D82-R156, collection W. Moore, New York.
5. D82-R156, Stockholm, collection Martin Rowe No.QX. 5.16 g, 16,99 mm. (Coin No.4 in image above & below)
6. 2451 D82-R157?, Elsen J., Bruxelles, liste 29, fév. 1981, n 13. 7,29 g.
7. 2452 D83-R?, SNG Copenhague, Phoenicia, no 67. 4,36 g.
8. 2453 D84-R158, Londres, BM, 1930 2 6 13 E. Rogers. 3,20 g, 16,8 mm.
9. 2454 D85-R159, New York, ANS 1944 100 70662 Newell. 4,32 g, 17,1 mm.
10. 2455 D?-R?, SNG Fitzwilliam, Cambridge, no 6015. 5,06 g.
Please follow provided link for coins attribution;