Yes, I saw that one on fleabay.

My guess (and guess is all that it is), is that it might have been for a Japanese Domestic Market (JDM) AT1.

What the site really needs is a Japanese member with intimate knowledge of the bikes that were sold on the JDM!

I saw this on eBay too, I thought the guy had said it was off a JDM AT1 in a correction.
Here''s the bike I thought he'd shown a photo of the clocks.
I would think if you changed the faceplate it'll be the same as a DT1, maybe DEET could help.
www.carandclassic.com/car/C1361914

Mine are 7.5 red line including my aussie bike which is essentially a JDM …

Pedalcrazy do you have a ‘68 speedo you can sell me please?

cheers
T1

Good find Pete! 

Usual JDM differences are present - eg dual seat and front indicator location. Interesting that a green lens is fitted for high beam (no neutral or flasher lights?).

I had this tach save in my eBay watch list … it started out at £1000 GBP and dropped in £250 increments… here’s his description… he mentions Sebastian in France who I have communicated with and he seems very knowledgeable on parts tbf …

 

whilst no expert on the early ATs I have mistakenly purchased an aluminium front fender with the studs thinking it was 68 DT and it was for an 18” front wheel so assumed it was AT…..

interesting to learn that the early ATs also had small tacho … I’d love to see some official supporting evidence that this is correct ….

cheers
T1
 

My guess is that for the early bikes it was a generic tach as it was the first enduro tach. Other bikes have different redlines to match their engines. Betcha the 68 was so new that the first ones just used any tach available in 1968, regardless of redline marked. There are both redlines on several different DT’s that I have seen. 
Anyones guess is as good as mine. 
 

I'm finding the information that the first JDM AT1 models (Japanese models often predated the US model by a year or so) came with the higher redline tach to be most the most plausible source of the part. 

Model code 248 that Sebastian in France referenced is assigned to the 1968 Japanese market AT1.  Would be cool if any Yamaha historians out there had a picture of that model. 

If the higher redline doesn't bother you, great.  If it does, easy fix to have DEET rework the faceplate to be correct for a 250. 

"Would be cool if any Yamaha historians out there had a picture of that model." 

I think that Pete's link was for one that is for sale from Japan.

Whilst it may we’ll be AT1 … I’m sure that  it will get confirmed one way or another….. it may be actually quite rare …

if it were mine I’d keep it like it is for its rarity value … after all it’ll look right size wise for a ‘68 and very few people will ever know/comment …

cheers
T1

7500 or 8500, either way a very rare small tacho