Having just purchased Revell's 1/72-scale 88mm Flak, I notice two omissions: the semi-autonatic loading device, and the rammer (the long tube which runs parallel with the rear section of the gun). Were these items optional features of the weapon, or is this simply an error on the part of Revell? Studying other people's models of the 88mm Flak (in both 1/72 and 1/35 scales), I see that these are often without the attachments.

Yes those were deleted in later production runs (Flak 37) and sometimes removed from guns that already had them attached.

Here's a link to a video of 88's in action.

http://www.youtube.com/watch?v=sElNyLusnNU&bpctr=1360724814