mhm, we imported several late 60s Sunns from the US, a.o. a 2000S, and gave them to Tube Amp Doctor in Worms, Germany to change them from 117 to 230V - this did never require a special or new transformator, so I think the original trafos must have connections for 230 V also, so an normal original trafo should do - anyway, I can recommend the Tube Amp Doctor for your purpose ...oh I just see your post is already pretty old - did you already fix it?