Need help on original version Art Audio Concerto

I am trying to get a copy of the manual. I've tried Art Audio without success.
Does anyone know the difference between the original version and the Concerto II version?
Has anyone tried tube rolling with either version and their experience? What power cord works well?
Much Thanks,
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I have one too. Did you find any info? Can you tell me which position the small valves fit in the Concerto?

I have a pair Mullard 8136 and Harma sq6922. Not sure on position?

Tried phoning Art in UK but no answer