FORVM recently offered this unidentified coin for sale. Given that there was enough of the obverse legend to identify it as a coin of Geta Caesar and there was a substantial amount of the reverse legend visible I figured it must be worth the $22 they were asking as it ought to be identifiable.
The left hand side of the reverse clearly reads SELEVKI in Greek letters, whilst the right reads A ABIL.... It has to be a coin of Abila in the Arabian Decapolis.
The only problem is that there is no coin of Geta listed in the appropriate British Museum Catalogue of Greek Coins for the region, nor is it listed in Spijkerman 'The Coins of the Decapolis and Provincia Arabia'. Lindgren I and III list no such con and neither do the British SNG volumes. It is also not represented in the American Numismatic Society SNG volume.
It would appear that this is a new coin of Abila, previously unrecorded.