Thanks! I legitimately wasn't sure if that sort of thing counted...

Papal States, Bologna
Pope Clement XI (1700-21)
(Billon) muraiola of 2 bolognini
19 mm, 1.28 grams
Obverse: [CLE]MENS.XI.PON[.]MA, bust right (presumably of Clement XI)
Reverse: [S.PE]TRONIVS [DE.BON.], St. Petronius standing (with assorted background objects I'm not sure of the identity of)
In hand, a lot more detail is visible; might try to take better pics later, though the pics here give a good idea of what I saw when I bought this.
A few of the letters in brackets are in fact just barely readable in hand.
In retrospect (and guided by the CNI description), I think the second pic might be upside down. That's probably Petronius's saintly cap at 5:30.
(Yes, you can't see anything at 5:30 here, that's the photo's fault. In hand it's so clear I'm not sure how I missed it.)
Lamoneta.it W-CXIBOL/9-16, CNI 202 (vol. X p. 242)
Cf.
Numista 152990 (technically the same type)
...Attributing this had been an exercise in confusion.
Stage 1, at shop:
- It clearly says XI on it. Someone the 11th.
- It looks 17th or 18th century. Way too late for Louis XI. Could it be Carl XI of Sweden?
- That name before the XI doesn't look like Carl to me.
- To be honest, it doesn't look much like
anything to me. What the triangular heck is that name?
- Whatever. Looks cool. Let's buy it.
Stage 2, at home:
- Load up Numista, search for "XI".
-
878 results found- ...Oh, right. Search for "XI"
in lettering.
-
485 results found- Ugh. "XI" in lettering
and 18-21 mm diameter.
-
50 results found- OK, that's manageable. Let's see if any make sense...
-
sees the Clement XI coin- Oh, right,
Clemens XI! I
thought that name looked weird.
Stage 3:
- OK, so it's Clemens XI.
- There's a bunch of similar coins, though.
- I thought it was the Bologna one, but it has a bust left. This is clearly bust right.
- There's a
Ferrara one with bust right.
- Would be a bit sad if I had a boring St. George instead of a cool St. Petronius.
- (I actually thought that.)
- Wait, that clearly looks like it says Petronius on my coin.
- So it
is Petronius. Definitely not George.
- That bust looks wrong though.
- Also, if there are two [make that
three, actually], there might be more. I know Numista is incomplete. Let's see what Google says...
Stage 4:
- [assorted unsuccessful googlings skipped - I don't actually recall what exactly I googled]
- OK, that doesn't seem to work.
- (I found a few examples, but they're all either obviously wrong or bust left.)
- I know of a blog that seems to have all kinds of Papal coins.
- [several more unsuccessful googlings later]
- I know I've mentioned in on CCF.
- [a few successful googlings later]
- Oh, right,
it's in French.
Clement XI. Not Clemens. That explains why I couldn't find it.
- There are 13 pages of Clement XI coins in there. Ugh.
- [a bit of looking through them later]
- OK, I found
one example where the bust looks right.
- No references though. And the legend doesn't
quite match either.
- Let's google it
again!
Stage 5:
- OK, so I know it's Clement XI, or Clemens XI, or Clemente XI in Italian apparently.
- And it's a muraiola, so let's include that too.
- (The blog spells it as "muraloia", by the way, but that appears to be wrong.)
- To Google Images!
- OK, so
the site with the listing of Italian coins has a bust-right photo.
- It also says the legend ends PROT BON.
- ...I think I can see BON on mine if I squint?
- Sure not what the pic says though.
- ...To the
other site with the listing of Italian coins!
At this point I go to Lamoneta.it, find
the entry, and realize that, as far as I can tell, the last line is an exact match for my coin.
And fix the Numista page, while I'm at that. (It didn't have a "no date" line when I started.)
[I apologize for the wall of text. Really wanted to share this though.]