Shortly there will be better photos of this coin more widely available after the release of the Witschonke collection images for the ANS. The obverse and the type of token is well summarized in a blog post by Clare Rowanwith references to further scholarship by Carbone, Stannard and others.
CNG listed the Reverse as a “Harrow (or miner’s axe?)”; The ANS presently has it as “Plow?” and another senior scholar assured me it was an axe. I’m not convinced.
I’ve been reading Ulrich’s Roman Woodworking and I think this tool is a far better fit with representations of the adze.
The adze is a planing type tool. This is an amazing discussion and collection of images. All the comparative images below are taken form this website. The thing to notice about the adze is how the handle curves towards the blade. Axe handles are typically straighter and longer.
The objection to it being an adze rather than an axe is that the blade on the coin is than angle of the cutting blade to the handle. This is explained by Roman perspective and is seen in other representations of the adze. On the below tomb the wide blade is represented with the two handled grip, the artist has chosen to emphasize width over true profile. The photographer above has achieved the same effect by viewing angle.
The adze in operation is represented on the Telephos Frieze from the interior of the Great Altar of Zeus at Pergamon:
Updated later same day
Ulrich was kind enough to write back and confirm in his opinion that it is most certainly an adze. He mentioned the representation under Icarus’ work bench on the Vettius fresco as another perspective drawing of a Roman adze.
Thinking more about the Telephos frieze … I got wondering if the Adze might be symbolic of boat builders generally. Perhaps!
Egyptian boat building scene 7th century BCE (Brooklyn Museum)
Adze and boat building further example (added 8.4.20):
Said to be from Chiusi