"Iconic" meaning readily recognizable or readily identified, leaves the broomhandle mauser, the Beretta, and the Browning out in the dark. The general public usually identifies any full size auto pistol as a "Colt .45" or "Colt Automatic." And, again, few no-gunnies know a Broomhandle Mauser from a Schmeiser. And movie goers wouldn't know a PPK from any other pocket pistol.
Show the gun in silhouette and see what answers you get, from you local church members or co-workers.
That is part of what I found so interesting- differences in what the public recognizes and why, comparing here to China.
While I would tend to agree with you about the USA public not recognizing a broomhandle Mauser [C96, right?] in any way/shape/form, in China it was one of the three most common toy guns on the shelf.
Of course, China had a bunch of them before/during WWII while the USA didn't receive many.
Kind of like the BHP is more recognizable in much of the world than here, because here the 1911 'ruled' the military handgun role until the mid 1980s [we won't debate if that change was good or not, but it isn't the 'go to' issue of the entire US Military any longer].
Since China recieved more of them than the US, it makes sense that they would have a larger role in the collective consciousness of the public there- and this would be revealed in the toys they choose to make.
But I like the lists so far of what should be Iconic, based on gun owner's understandings.