Looked back at the bill and didn't see any gasket charges on the axle work. Just listings for lubricant (part no. 5102232-AA) and cleaner (part no. 4897151-AB) under the parts column.
Big thanks, everyone. I'm a first-time CTD owner, learning as I go. I went the full convenience route on this particular service. But I'm thinking I can and should handle the easier stuff like fuel and air filters myself, if nothing else (would've saved about $100 in this case).
Thanks again -- TDR is a great resource ...
--JGLaneJr.