Re Tubing Audio Research VT200

When I had my VT200 I bought non ARC SED 6550's from a well known Canadian tube seller and found the pin diameter was slightly smaller than the ARC SED tubes. I had one arc, and it cost me $500 shipping plus repairs to send it back and forth with ARC. ARC does extensive burn in and matching on their tubes.
I did use the new issue Tungsols in a VT100 mk2 and found them reliable and good sounding. I also used SED KT88's in that amp without a problem.
The problem as you probably know with the VT200 is the HUGE power supply, which even though a dual mono design takes all the current from both channels through an arc'd tube, taking out a resistor and some traces. They make them that way for the best sound quality, but it is perilous to use questionable tubes.

The repair was about $150 or so, if I remember correctly. The problem is shipping ($500 round trip), which must be on a common carrier. I had to take off work to meet it, and no carriers would insure it on the journey. The best bet is to have ARC arrange pickup and return. When I sold it, I had to use a Pack n Send type business because they would insure it, but no carriers would.