16610 v 16613 differences

[CaptainJack]

Hello everyone,
I'm curious if anyone can verify or chime in on this question.
I bought a 16613 through a dealer on EBAY (yeah I know), had an appointment
with my local AD's Rolex certified tech on the day of delivery and he did an appraisal for me and verified it was a gen watch.
Recently, a friend got a 16610 from the same dealer and when I was comparing
the two using a strap on loupe, I noticed a slight difference in the lettering on the faces.
The 16613 lettering on the lower half of the face seems (does) to have "points".
If you look at the "I" in submariner, it has very small points at the very top and bottom (left and right). My friends 16610 didn't seem to have that level of detail on the lettering.
The fineness of the machining on the back cover of the watch (the part that sits on your wrist) case seems to be different also. Where mine is a very fine finish, his seems to be coarser.
I guess I should mention that my 16613 is the Champagne Serti dial with the diamonds and sapphires.
Is that why there is a difference between his sub and mine?
I'd include pictures, but my digital camera doesn't focus down close enough.
Thanks for any thoughts or input.
Jack
BTW, both of these watches are used "Z" models.

[mic6]

rolex lettering can vary depending on where the dial was made

they have several factories around the world

[CPTL]

Yeah, dial printing always varies from one printing to another printing.

[Rscmaine]

And the 'smoothness' of the case back is a question of how much the watch has been worn - and whether it was on the smooth wrist of a young'un like Kyle or a hairy old B***ard like JJ!

[CaptainJack]

Originally Posted by Rscmaine

And the 'smoothness' of the case back is a question of how much the watch has been worn - and whether it was on the smooth wrist of a young'un like Kyle or a hairy old B***ard like JJ!

Hey Rscmaine,
First off, thanks guys, you've answered the face question. But on the subject of the case back,
I'm not talking about a watch that has enough wrist time to wear down any machining on the case back.
These were both in mint condition, no signs of wear at all. I even asked the
watchmaker at my AD if it looked like it had been buffed or polished and he said
no. He, btw, is one of the few factory certified guys available in Oregon.
No, the fineness of the machining on the case back is definitely better on my 16613 when compared to his 16610.
Jack