I wonder if the OP coin was struck for presentation, perhaps to some minor dignitary or such? The flan is highly unusual and suggests a special edition.
I took a new picture of mine, (year 12) i got back some time ago. little larger than MNoob, i did see one at the Boeing show, it was about 100 MM or more. i didn't think it was real. Had to lower it to the bottom of my camera bed.
That is a fantastic follis with great patina! You got great eyes and a lot of luck spotting gems on ebay. Congrats! It is a very popular type with a lot of character in them. Justinian is quite popular with the coin masses. If you look on the lower right (his shield), you can see Justinian on a horse. Some coins have it done nicely, while others are somewhat abstract. Yours is nice! Here are some of my Justinian coins: Byzantine Empire: Justinian I (527-565) Follis, Nicomedia (Sear-201) Obv: D N IVSTINIANVS P P AVG. Helmeted and cuirassed bust facing, holding globus cruciger and decorated shield; cross right in field. Rev: Large M; cross above, B below. A/N/N/O-XXII across field; in exergue, NIKO. Byzantine Empire: Justinian I (527-565) Half Follis, Constantinople (Sear-165) Obv: D N IVSTINIANVS P P AVG. Helmeted and cuirassed bust facing, holding globus cruciger and decorated shield; cross right in field. Rev: Large K between ANNO - XII, cross above; E below. Byzantine Empire: Justinian I (527-565) Half Follis, Nicomedia (Sear-203; DOC-154; MIBE-116a) Obv: D N IVSTINIANVS P P AVG. Helmeted and cuirassed bust facing, holding globus cruciger and decorated shield; cross right in field. Rev: Large K between ANNO - XXXII, cross above; NI below
I got lucky a few years ago with several awesome Byzantine coins in an auction (my first Byzantine coins, BTW). Guess it wasn't as popular as it is now.
BTW, I am personally on the hunt for one of Justinian's plague coins. Justinian caught the plauge around 541/542 and hence the follis and half follis was altered to depict this. Typically, when someone has the plauge, you end up with swollen lymph nodes and hence your face and neck get swollen. See the differences between the Justinian folles: I missed out on this beauty a while ago when I didn't know better : The reference to this coin can be downloaded from academia.edu: https://www.academia.edu/10372470/Lempereur_Justinien_survivant_à_la_peste_bubonique_542_
After responding to this thread, I, interesting enough, found and bought a half-follis! You normally don't bump into these as I have been looking, at least, in the quality I was looking for. Feast your googly eyes on this beauty. Different from my previous Sear-165 I posted two threads up... Byzantine Empire: Justinian I (527-565) Half Follis, RY16, Constantinople (Sear-165) Obv: D N IVSTINIANVS P P AVG; Helmeted and cuirassed bust facing, holding globus cruciger and decorated shield; cross right in field Rev: Large K between ANNO - XЧI, cross above; Λ below
Alright! Lets get the party started. I'll give Sicily the boot (sorry Catania & Syracuse), while I go through Rome and Ravenna... Byzantine Empire: Justinian I (527-565) Æ Decanummium, RY 36, Ravenna (Sear-326; DOC I-353; MIBE-229a; Ranieri-395) Obv: Helmeted and cuirassed bust facing, holding globus cruciger and shield Rev: Large I flanked by date; all within wreath Byzantine Empire: Heraclius (610-641) Æ Follis, Ravenna, RY 23 (Sear-915; DOC 302; MIB-254; Ranieri-610) Obv: Figures of Heraclonas, Heraclius, and Heraclius Constantine standing facing, each crowned (except Heraclonas who wears a plain cap) and holding globus cruciger; cross to upper left Rev: Large M; monogram above, A/N/N/O to left, X/X/I/I (date) to right, Λ (A without crossbar) below; RAV A filler coin I picked up that was somewhat dirt cheap. I'll have to upgrade this one... Byzantine Empire: Tiberius II Constantine (578-582) Æ Decanummium, Ravenna (Sear-472) Obv: DM TIB CONSTAN PP AVI (or similar); Crowned, cuirassed bust of Tiberius II facing, holding globus cruciger Rev: Large I between two crosses; all within wreath