Here is reference 104602 picture from Polerouter website:
https://universalgenevepolerouter.com/galleries/204602-104602-404601-polerouter-jet/
Polerouter Jet watches with calendar movements generally will say “Date” on the dial. I have seen similar dials, but this one is missing the gold frame around the date. So some work has been done on the dial. I just can’t tell exactly what was done. BTW, I have been told by UG that the dials on Jet models are not gold, but markers are gold.
Case and movement look OK to me. Although I don’t like that seller implies that there is 40g of gold. The movement is going to weigh over half of that. The Jet models were designed to be slimmer and weigh less than the regular Polerouter models.
Hope this helps,
gatorcpa