Academia.edu is a great site for having academic articles about ancient coins. It sends me emails when articles I might be interested in are posted, and I just got one about this Republican type which I happen to have: Denarius. 18 mm. 3.92 grams. C. Allius Bala, 92 BC. BALA behind female head (Diana?) right, letter before but much too weak to be certain, maybe an E. Biga of stags right driven by Diana, dolphin below. C.ALLI Crawford 336/1c. Sear I 221. The article is a CUNY master's degree die-study here: https://www.academia.edu/4333871/final_combined?email_work_card=view-paper It is 144 pages with 83 pages of photos of denarii, 4 or 5 per page. If you have one of this type, it might be illustrated there. If you are not an academic you can still sign up with Academia.edu as an independent researcher and get access to many hundreds of interesting articles on ancient coins. Can you show us a another coin that has an article available for download from Academia.edu about the type?
I agree that academia.edu is a fantastic resource. I use it a lot, but here's my latest relevant coin story. Coins of Charlemagne are very expensive, even if in miserable condition. But on the strength of Simon Coupland's article on academia here, I bought this coin: These deniers from Melle are not normally attributable definitively to either Charlemagne or Charles the Bald in the absence of archaeological context. But in the above article, Coupland notes that deniers with any of the following features are more likely to have been issued under Charlemagne: 1) neatly produced, with an obverse legend cross that occurs at 1 o’clock with respect to the monogram (oriented vertically) 2) uses a barred A 3) has a chevron in the central lozenge of monogram This coin has all three of these Charlemagne indicators, so I conclude it is much more likely to be a Charlemagne coin than a Charles the Bald coin, and I got it for far less money than an unattractive coin definitively attributable to Charlemagne. In addition, it's a beauty! I'm very happy to use it to fill my Charlemagne slot, even if I can't be 100% certain about it. (If you see a similar example with all three characteristics, I recommend snapping it up. They are not easy to come by!)
I will download the article! Here's my Allius Bala, with a grasshopper beneath the stags: An example of another article available for free download is this one: Hersh, Charles A., “A Study of the Coinage of the Moneyer C. Calpurnius Piso L.f. Frugi,” The Numismatic Chronicle, Seventh Series, Vol. 16 at pp. 7-63 (1976). See https://www.jstor.org/stable/42664788?seq=1#metadata_info_tab_contents). Then there's this one: Bernhard E. Woytek and Kevin Butcher, The Camel Drachms of Trajan in Context: Old Problems and a New Overstrike, The Numismatic Chronicle Vol. 175 (2015), pp. 117-136 (https://www.jstor.org/stable/43859784).