So as a follow up for this thread, after a bit of searching and asking
around I got in contact with the builder of the RV-9A (not RV-10...)
that had the latches I posted here about, and he looked closer at his
latches for me last time he fle, ( http://www.n523rv.com/fuselage/Cowl%...%20outside.jpg,
same pics as before
and http://www.n523rv.com/fuselage/Cowl%...h%20inside.jpg )
revealing them to be Hartwell 4050-S081 latches for those who care...

Searching for these latches was another thing entirely, as the closest
I came up with was:
http://catalogs.google.com/catalogs?...Hartwell+H4050
Luckily Dan Brown at B&B knew exactly what I was talking about when I
called him with part numbers and descriptions this morning, and had
(past tense!) 15 left for a good price. Packed them up and shipped
them to me with a bill and an address to send the check to, despite
the fact that this is our first dealing. I just love mom and pop
aviation suppliers!

-Paul