[OTR-users] Where are the OTR-Private and OTR-Not Private buttons stored?

[Jason Cohen]

I would like to replace the default text "OTR-Private" and "OTR-Not
Private" buttons with something that more clearly shows the status of
the connection. Gaim-Encrypt's button shows a red lock icon for
encrypted communications and a unlocked grey icon for unencrypted
conversations (or a green unlocked icon if encryption is available but
not used). I was thinking of replicating this for OTR but instead of
using Tx;Secure and Rx:secure I would simply have the text say
"OTR:Secure" and "OTR:Insecure". However, I can't seem to find the
location of OTR's button? Anyone know where I can find it, or the name
of the file so i can search for it?

Here's a screenshot of what the gaim-encrypt icons look like:
http://gaim-encryption.sourceforge.net/conversation.html

Jason