It seems legitimate and not to worry, the day wheel has the right code printed on it.

If you are asking can an April 1970 6139-6010 in particular have a Portugese/English day wheel, why not?

Here are the known languages for the 6139 caliber:
for the 6139 series, we have English with:
Kanji
Roman
Spanish
German
Arabic
Italian
Chinese
French
Portuguese
Thai
Farsi

Happy to add as needed.

Congrats on a nice one. My various 6139-6010s say hello:

 

Thank you much for your reply. I was starting to question the variant’s existence given how little documentation there is online about Portuguese day wheels on the 6139-6010 specifically.
Your collection is stunning, especially that brown dial version. Really appreciate you taking the time to share the known language list and confirm Portuguese is legitimate for the 6139 series.

 

I have a sex on Friday 6139 but it's a 7070 case model, old photo.

 

So I’m not alone! It must be a rare variant. Thanks for sharing.

 

I would be careful, someone's been messing with this one. Both of the chrono hands are incorrect. It's been polished. Who knows what else has been done to the watch. A caseback photo would be nice.
Here's what a -6010 is supposed to look like.

 

Yes, your observation is correct. The seller told me he bought his in Brazil and the chrono hands were not original. I had it just serviced and was assured everything else is age appropriate and original. I’ll have to change the hands at one point. I include more photos here.

 

Aloha ,

Hello,

New member here with a question about my 6139-6010 ( April 1970). It has an English/Portuguese bilingual day wheel. The watch has been serviced and authenticated as period-correct by a specialist, but I’m trying to find more references about the Portuguese day wheel.

Questions:
1. Has anyone seen factory-original Portuguese day wheels on 6139-6010 cases?
2. Which markets were these intended for?
3. What authentication markers should I look for?
I can post more photos of it helps.

Appreciate any insights from the community.

Aloha Alex,
Well it could be true and I am ....... Half Portuguese also and I am from Hawaii but I never had a 6138 watch at all.
Brazilian People do speak and are of Portuguese Nationality also. Hawaii we have a lot of Portuguese People also.
Louis in Hawaii

 

Hello,

New member here with a question about my 6139-6010 ( April 1970). It has an English/Portuguese bilingual day wheel. The watch has been serviced and authenticated as period-correct by a specialist, but I’m trying to find more references about the Portuguese day wheel.

Questions:
1. Has anyone seen factory-original Portuguese day wheels on 6139-6010 cases?
2. Which markets were these intended for?
3. What authentication markers should I look for?
I can post more photos of it helps.

Appreciate any insights from the community.

Hey, welcome!

As others have said, there is indeed a portuguese day wheel by seiko, and for the 6139 for sure. Theres actually another post on the matter as well, with pics that match yours: https://www.thewatchsite.com/posts/3019005/

Now, as for your second question "Which markets were these intended for?", i think it's pretty obvious they would be for portuguese speaking markets
Interesting thing though, the wheel is labeled EB which would stand for English / BRAZILIAN. However, there isn't really a brazilian language, it's actually portuguese. Portuguese from brazil, or brazilian portuguese, but portuguese nonetheless. So i just find it interesting that the wheel is EB and not EP. Maybe there's another language that starts with P in these wheels, or could just be a simple fact that brazilian market is/was much larger than portuguese market (by country size and population overall)...

I have seen a few 6139s with portuguese day wheels, but have also seen them in 6138 and 7016 at least.
Another interesting 'marker', if you will, is that watches that were bought in portugal specifically, would've had a hallmark punched somewhere on the case (front or sides usually), and this wouldn't be the case in watches from brazil. So while the language wheel is the same, sometimes you can tell where the original market was as well.