When I bought an XJ12-300 mini mill from Amadeal way back in the 2000’s, I also purchased a number of other accessories at the same time as we were living in France at the time and I picked up the mill and bits from Amadeal while on a visit to the UK. One of the extras was a collet set with seven collets. Not knowing any better at the time, I assumed that they were ER25 collets, but they turned out to be close but not quite. I sold them on with the mill when I returned to the UKin 2015, but I’ve just dug out an old photo from one of my old albums on the old forum and they look remarkably similar to the set currently offered by Amadeal on their web site, HERE.
It looks to me as if the taper of the collet is less that that of an ER25 set, though that may be the perspective of the photo. It’s possible that David’s set is one of these. Maybe a ‘phone call to Amadeal could elicit confirmation, one way or another.
John