I have been using a vintage step-up (UTC A11) between my preamp Kondo M7 and my cartridge Lyra Skala. The match was really good.
Or any other combination that match well (the UTC transfo are not easy to get in Europe ...!)
How was the the A11 wired? The A11 supports 50Ohm, 200Ohm and 500Ohm primary impedance, so to make a useful recommendation it would be necessary to know which of these you were listening to and found to be such a good match.
The Skala has an internal impedance of 5.5Ohm, so I would assume it was either the 50Ohm or 200Ohm taps, but that’s no substitute for knowing for sure.
The Verion/Cotter transformer is likely a very good one, but there are scores of excellent SUTs available and only one with specs matching the one heard by the OP will sound (more or less) the same. Just throwing out names of good units isn’t really that helpful in relation to the actual question.