Duotone build history

A German ebay auction offers an early 90s MIK Duotone. I wanted to tell the auctioneer that this might be an Echtone as it is a MIK built guitar.

To my surprise, he came back with the information that early Duotones were built with an f-hole and later on were switched to 3-holes before eventually being switched back to f-holes again.

The Echotone has two f-holes of course. Hence, there was a wrong thought on my side anyway, but...

Can anyone lift me up to the true Duotone history?

the USA Duotones from the 90's up until the factory move to Connecticut had 3 sound holes. After the move to Connecticut, the USA Duotone was replaced with the USA Duotone Custom. That had an arched top with a single F-hole (and had crown or victory inlays and a bound fretboard). Somewhere in between that time frame Hamer also sold a Korean made Duotone. It had a flat top with a single F-hole (with dot inlays and no fretboard binding). Without seeing a picture of the guitar I would guess the seller has a late 90's Korean made Duotone (or perhaps an Ecotone as you stated). A 6-digit stamped serial number on the back of the headstock (or lack thereof) will also be a good indicator if it's USA made or not.

Correct. There are no 3 hole imports, and no flat-topped F-hole USA Duotones.

The MIK scored 300 Euros ... to have this saved to the archives. It included updated acoustic electronics to the original USA version.

IIRC, some of those early MIK ones had neck angle issues that resulted in higher than normal action. It was resolved soon enough but I wouldn't buy one sight unseen. I don't think they were terrible....just higher than one would expect from a Hamer.