Everybody is posting some really nice carving... but most of it is definitely not in the "not difficult to carve" category. 
Consider the simple, basic fleur-de-lis that goes with the Christians' Spring/Lancaster style of carving you already have on the gun.
It's a relatively simple design, not too much three dimensional sculpting, fairly quick to do with a V Parting tool, and can be embellished if you so desire.
Is this even relief carved at all? I think it looks perfect for my skill level.
Yes, it is relieved. This is how I see a LOT of 18th century gun carving, particularly of the types of guns that I like to do. The carving is relieved with incised edges. The carving does not have to be so high, and the incised edge gives the appearance of greater depth (and, of course, more definition). It's also how the carving can flow seamlessly from relief to pure incise, like scrolled lines flowing off of raised features.
It is done with a fine angle V Parting tool, NOT a Veiner. (a Veiner is a small U gouge). Incise the design perhaps a bit deeper than one would if just doing incise carving, and then level down the background up to the incise line, leaving some of that line there (deepen, if necessary). If you have the hand and eye for it, it can be done VERY quickly. FAR faster than stab, stab, stab, stab, hunt for a gouge, stab, stab, look for a different gouge, stab, stab, stab.... It's basically wood engraving. I only stab in with a gouge on certain things like the little "((" marks or for some odd, small, or hard to do shapes. As with incise carving, there is no room for error, though, and you better not slip!
I have gotten to where I pretty much do everything this way now, even if I don't want an incised edge on the relief part.
I am not the greatest wood carver. I'm fair. Hampered mostly by my impatience, which is what keeps me from being great!
