Are all Puchs with Columbus frames made outside of Austria?
I have a mid-eighties Mistral SE with 531 that is made in Austria.
I have seen some, what I presume are later models, with Columbus tubing.
These are Bianchi-made, right?

My 87ish Puch Mistral, is supposedly made for Bianchi in Japan. The Label is Columbus SLX, but I think that is regarded as a Bianchi SLX combo of other tubes.

I don’t know if the tubing manufacturer was so restricted but I do know the top of line Puchs in late 1980s were made in Italy by Bianchi. I had a Puch Mistral Professional and Bianchi Superleggera side by side (both brand new) at VeloSport in Berkeley and other than the pantographed Cinelli stems and fork crowns that were embossed with their respective brands, they were identical beneath the paint and decals. The Puch was significantly cheaper so I bought the Puch. I was always a little rebellious in a punk-rock way so I pulled off the decals and re-decaled as a “PUKE”

Neat looking bike. Tape seems made for the bike (maybe it was?). Can't answer your question, but I'm curious about the added cable clamps on the top tube. What's their purpose?

Paint scheme and decals are what mine had before pulling the decals off … except for fork, mine is painted. Mine was speced with the then new Campy Chorus gruppo. (yours may have been rebuilt). As I recall, however, mine said made in Italy and again the frame was identical to Bianchi except fork crown:

It is my understanding that although my bike does carry a "Made in Italy" sticker, Bianchi did outsource many frames to Japan.
I may be wrong, I can't find any specific info at the moment.

smd4
The extra cable clamps I added because the outer brake cable I used is very stiff and made me nervous about my top tube cable guides. If i change that out, I would probably remove the extra clamps. I am fine with it as is, this is not a museum piece, no original fork, Shimano TriColor.

The bar tape is by BTP down under, I tried a couple of different combos before I got this one that matched.

I had the same concerns about using brake cable sheathing that's too stiff. A few years ago, I bought a set of brake cables from V/O that had braided sheathing and was surprised when I received the set and found out that they were very stiff and resisted being bent into curves strongly. I thought I could soften them up by "massaging" them a bit, but it did not do anything. So I ended up not even using them on my bikes, cause I could see me breaking the brazed on cable guide, nearest the head tube, after some time from fatigue.