Here are mine (to date): Old one from 1943: Polerouter estimated 1960/61 And lastly the Monodatic, apparently very first series (1951/52). You can see the case design from Genta that was then used in the Polerouters : None of your buckles would suit me !!!
Only impression is that if you actually ask, this means something to you ! But this is just my personal opinion, I am not the one buying it ! Good luck in your choice, as it is such a remarkable watch.
The following website is the absolute Bible when it comes to Polerouters: with all the details, references calibers etc... Mine is not i great shape but I got it at a very good price: Ref. 204605-3 One of the very first of this reference (serial number from the first 20 issued), caliber 218-2: