You know as much as I do. It's a topic worthy of close attention moving forward. There is some question, ironically for me, whether the first channeled tube builder was Colnago or - wait for it - Picchio. My early 80's Picchio has "rigidio" channeled tubing - including fork blades. though my frame post-dates the first Nuovo Mexicos.

^ I'm going to dig around a little this weekend, then. I also want to see the earliest example of the long channels on the inside of the chainstays - my '83 has these as well, and I wonder if the hype stated that with these channels and their resulting rigidity, Colnago could dispense with shoring up the chainstays with a buttress.

I'm pretty sure one way or another, the original fork did in fact have the more aerodynamic fully-sloping crown - it seems that was a major design change vice seatstay caps or even the BB shells...

DD

I'm going to try another LBS to see if they have this tool.

1. I have decided to paint the frame, no powder coating.
2. I'm going to solder on new cable guides.

Thanks for all of the great information, much appreciated!

Sure got me. I am no Colnago expert. I had crash my Gios into a car that got into the race corse. No body gave a damn about Junior races. It was 1985. I got insurance money in hand and went to Celo Europa for a Colnago. I wanted a Mexico or the latest and the greatest from Ernesto of course. I was told that was it. I search and search for the next new thing. These were the years way before the net. Only magazines and shops that imported Italian bikes were the go to places. I went to almost all of the big shops in socal looking for it but they all had the round SL (I think they were SL) frames. I ended up with a Medici. The best touring bike for racing, as the guys in the club would say, for 300 bucks. Two years later, I see this crimp tubing that suppose to increase strength and stiffness. it was the newest thing coming out of Colango. I was super pissed at Marcel at Celo Europa for getting me the Medici. Well, at least the racing continued.

By '85, Marcel should have been able to order you up a Master, or even the rare Master Equallaterall:

https://bulgier.net/pics/bike/Catalog.../85prices3.jpg

This thread reminded me of this thread: https://www.bikeforums.net/showthread...=%27colnago%27

I'm not sure if it'll help dating the op's bike.

I'm probably the only one on this thread who doesn't know, but - what is the best way to strip the paint as you did?

solder or braze? Not sure how durable solder would be, might be Ok on cable guides. Might be a detail question on the frame builders sub forum.

brazing is how most are done.

solder= lead/tin mix of metal that is used as "glue" between 2 metal parts. Relatively low temps required
Braze= brass mix if metal that is used as "glue" between 2 metal parts. Relatively high tems required (steel will be red hot+)

The respray on this frame was really thick so I started with some Rustoleum paint stripper, scraping off as much paint as possible then sanding with 320, 400, and 600 grit sandpaper (wet and dry). Since these pictures were taking I have done a lot more work with wire brushes and brillo pads. It is so important to have a clean frame when you repaint that spending the extra time to clean off all the old paint will pay in dividends.

Actually silver solder which is somewhere inbetween. The job will be good enough for hold cable guides, maybe not so much for cable stops. I'll post pics when I'm done.