The part right under the tail fin; you mean where the APU exhaust is?
The aircraft has rivets in some locations but they are flush set, so all you see is a little circle, not a bump. Fred is quite right when he says you won't see much in your scale, a 1/2" diameter rivet head would be only 5 mil at 1:100. I can't begin to suggest a means of showing a row of 5 mil flush circles.
Could you not keep it from turning into a travel agent 'toy' if you gave it other suitable detailing and some subtle weathering?
I usually model ships; one common problem with ship models is the modeller tries to put too much detail onto a model that is 1:350 or smaller, and the end result looks clunky and unrealistic.
Best of luck, whichever way you proceed.
Bruce