Oil Gallery Plug Under Transmission Cover?

[markb]

There's an interesting discussion going on at the SOHC4 site regarding this topic.  Take a look at the hole (circled in red) and tell me if you ever saw a plug for this hole.

Here's a link to the thread:
http://forums.sohc4.net/index.php?topic=99721.0
It has me really curious.

[hondasan]

Sandcast bikes rely on the gasket to seal off the end of that oil gallery. "Later" bikes use a rubber plug which has a lip that sits in a small shallow counterbore at the end of the gallery to seal off the gallery. I have never come accross any reference to this plug in the parts lists, and have no idea when it was first fitted.

Chris R.