Greetings,

I need help to identify the model of this frame: imgur.com/a/pzMoU
It does not have the original painting... The seller claims that it is a Montello. Can someone confirm this?
Any thoughts about its value?

Thank you.

Looks like a Montello,
The absence of a chain stay bridge is one sign it is, but I cannot get a good view of the top of the bottom bracket she'll from your pics. A Montello would have two reinforcing triangles on top of the BB she'll with the Pinarello "GTP" symbol cast on it.
Value will depend on the condition of the finish, and chrome, mostly. Some will pay quite a bit more if in some way, the notoriously fragile decals the Pinarellos came with, had survived in perfect condition. With what I could see in the pics, as is, I think it could sell for as much as 500 bucks. If the paint and chrome cleans up to near new condition, you might be able to add another 200 bucks in a hot market. In mint condition with pristine, original decals, maybe up to 700 bucks. Find two really aggressive Pinarello collectors to bid against each other, add another 100 to 200 bucks to that.

I'm not convinced it is a Montello. Pinarello made several others bikes in the 90's that lacked a chainstay bridge. This one is missing a few details that I'd look for in a Montello. Besides the triangles on top of the bottom bracket shell (which may or may not be there), it seems to be lacking the "flower" cutout in the lug above the bottom bracket, and there should be a small "GP" logo just in front of the seatpost binder bolt. Finally, if those seat stays were ever chrome they don't look like they are anymore.

This frame appears to match up better with the 90's Treviso on randyjawa's site: PINARELLO TREVISIO - INTRODUCTION

As I noted, I could not see the details on the frame because the pics (the pics are too dark when viewed on my smart phone). I just borrowed and fired up a laptop at home to look at them again and you are right about the missing "GTP" pantograph on the seatpost clamp ears and the suspiciously dull seatstay finish which should be a brilliant chrome on Montellos.
Also missing is the light color (usually white on their blue bikes) infill on the GTP panotgraphs and the flowers cutout on the frame.
Now seeing all this, I agree that this looks suspiciously like a Treviso, maybe made to look like a Montello by stripping the chainstay paint to reveal the dull chrome under the paint (I think the Pinarello frames were chromed all over, but the painted over areas did not have the good finished chrome on them.). The Treviso is still and excellent Pinarello, made with Columbus SL tubing, instead of the SLX used on the Montello., but market value is up to 1/3 less than Montellos. This possibly faked one to look like a Montello would even pull in less because of the "tampering" done to it. Do not buy this one, unless the seller sells it for a bargain. It's still a good bike and maybe it can be restored to be a Treviso again with just a little bit of matching paint on the chainstays and a Columbus SL decal on the seat tube. Heck, the downtube decals still looks good, and that's a plus on any Pinarello.