Dating a classic Pinarello

[chusma]

Hi!
This is Chus, from Spain.
Could anyone help me dating my Pinarello?
I can read A057 and R546 stamped in the bottom bracket shell.
I have not seen a b.b. cable holder like that, maybe it's a repair or upgrade. Also, seat tube stickers aren't correct either as the frame hasn't got bolts there.
Thanks in advance.
Chus

 

[highlandsflyer]

Looks like the Tre Cime. Pinarello's numbers are not consistent, but it has the internal rear brake. So early 80s?

 

[vtwinvince]

When did they start internal TT routing?