Yes Carpetsahib, that's correct. When you look over the Pan from the side you should see the flash hold as if it were sitting on top of the pan or about 80% of the hole in some cases (depending on the lock used)
If you'd like to learn more go to the Traditional Muzzleloading Association's web site, and to the gun building forum. I did a tutorial on building a flintlock for them.
Here's a link to it
http://www.traditionalmuzzleloadingassociation.com/forum/phpbb2/viewtopic.php?t=6214
I hope it will be helpful to you.

Steve