Bushmaster, what you have to be careful about here is that, until you've looked at a few, what appears to be a sidelock can actually be a boxlock with sideplates (which make it look like a sidelock). As noted above, on a sidelock, the lockwork is connected to the sideplate. On a boxlock, even if it has sideplates, the lockwork is contained within the action itself. Some makers (Bernardelli of Italy being an excellent example) went to some lengths--including putting false pins, screws, etc on their sideplates--to make their sideplated boxlocks look like sidelocks.
If in doubt, ask--with a picture if you can post one. And don't feel like the Lone Ranger if a sideplated boxlock fools you. I've seen dealers describe Bernardelli boxlocks as sidelocks. Another one of those you can look at currently would be the sideplated Fausti Dea, offered by Cabela's. That one doesn't have all the pins in the right places, but some people might think it's a sidelock.
