Trying to i.d. this Pinarello frame I bought many years ago on eBay and only recently took off the garage wall. Features (from rear to front, more or less):
1. Pinarello rear drop-outs (chrome)
2. Chain hanger braze-on.
3. GP pantos on top of seat stays.
4. Columbus SLX sticker on the seat tube (but I can't detect any rifling inside the ST when looking/feeling through the left side of the BB shell (right side fixed cup is still stuck/seized, so no view/feel from that side). Did Pinarello use SLX for any frame other than Montello?
5. Front derailleur braze-on (chrome) with GP panto.
6. One-piece BB shell, but does not have GP pantos on the top side (so, not a Montello?).
7. Gear cable channels go through the inside/underside of the BB shell (not over the outside through a welded steel or screwed-on plastic guide).
8. Underside of BB shell has "PINARELLO" panto and serial no. 1S 409 (which matches the serial no. on the fork's steering tube).
9. No bridge connecting the chain stays.
10. Right chain stay (only) is chrome; rest of rear triangle is blue like rest of frame.
11. Seat tube and down tube braze-ons for water bottle cages.
12. Shifter braze-ons on downtube.
13. (Unusual) braze-on on the underside of the top tube (for frame pump maybe?).
14. Internal cable routing in top tube ("in" and "out" are both on the top of the tube).
15. "Olympic Champion/Tour de France 1988" decal between shifter braze-ons on down tube.
16. Oval head tube decal with image of cyclist and horizontal colored stripes and words "PINARELLO" and "ITALIA"
17. Chrome fork with painted fork crown and "Columbus" decals on each side; GP pantos on each fork crown.
18. Pinarello drop-outs on front fork.

I've gotten some help on Facebook, with one suggestion that its a Treviso given no rifling and no GP pantos on top of the BB shell (so, not a Montello). Obviously hoping it was a Montello given the SLX decal on the ST, but the more I look at it, I think that decal is newer than the others and was added later (to move it on eBay perhaps?). But then what do I make of the internal cable routing? Did Pinarello use internal routing on frames other than the Montello circa 1989-1990?

Any help is appreciated. Looking to build it up with period Campy components and use it together with my old Cadore. How much I spend on the components may depend on quality of the frame.

It looks like a Montello to me, no bridge on the chain-stay is usually the giveaway.

I've seen many Montellos with the same amount of chrome that this frame has, it would seem that for some production years Pinarello put less chrome and pantographing on the Montello.

It may also depend on the market that the frameset was sold.

Two things-
The graphic on the rear drive side of the top tube? A name?
I did not see the mentioned top tube braze on.
I'm actually thinking a team bike of some sort. Not a top level team but a "continental" team.

Thanks for the input. What is a "team bike"? Is that a custom build by Pinarello that would depart from the standard frame sets at the time? The graphic you ask about appears to be a brand name of a Belgian clothing/accessories vendor, Bio Racer (Bioracer - innovative-custom-cycle-clothing) (see attached pic), perhaps a team sponsor? Also attached is a pic of the top tune braze-on that I do not recognize. Thanks again.

Two of my Pinarellos are late '80s/early '90s Montellos. Both are Columbus SLX. The rear triangle on mine are all chrome. Also, the fork is all chrome with no paint at all.

My Montello has a chrome fork with no paint and only the drive side chainstay is chromed. It is SLX.

That braze-on is for a race number, further evidence that your frame was built for a racing team and falls outside the standard fare.

Thanks to you all for your feedback. This frame has launched me on an odyssey. With your guidance and some info from other sources, I traced the frame to a member of the WCL Bergklimmers club in Stein (Limburg), Holland. Everything about the frame indicated a Montello (internal rear brake cable routing, no chain stay bridge, sloping fork, chrome...and of course the suspicious SLX decal on the seat tube), but there's no rifling in the seat tube and no pantograph on the top sides of the BB shell. So, I'm guessing it's a Treviso with SL tubing and the aformentioned special features ordered by the team (?). Now on to how to build it up...Thanks again.