Identifying Rolex

[fullofit343]

Hi All,

My grandfather has had this rolex for sometime, but it's origins are unclear. He insists he's brought it to Rolex to be serviced on a number of occasions, but based on my research, I'm not convinced it's genuine.

For starters, the watch is very light and not what you'd expect from a high quality timepiece. That said, I don't have another Rolex to compare it to - just other watches like Omegas and an Angelus.

The closest looking model I have been able to find is the 6263, but instead of the "Units per hour" being by the 3 o clock mark, it's up higher, which I haven't found on any similar looking Daytonas, which makes me question its authenticity. Any info would be appreciated.

Unfortunately I don't have the tools to open it up and take a look at the movement. These are the pictures I can provide: