Replacing 6550s with KT 88s

I have 20 low hour cryo'd Winged C's. I went back to KT88 and much prefer them for overall warmth and sweetness. Are the Winged C's hard to find since the factory burned down?

Arthur, Kevin Deal at Upscale just sourced a whole bunch of SED 6550 C tubes. Just bought one for my ARC Ref 5 linestage. Seems to work just fine. Price is still reasonable.

I procured a set of Genalex KT 88s from Well Audio Labs, Singapore,last week and spent the better part of the weekend comparing the 3000 hr+ Winged C 6550s with the new KT88s.What immediately struck me was that despite some 3000 + hrs there was little to choose between the 6550s and the KT 88s. There was a smidgen more smoothness and air in the upper frequencies. After extensive listening comparisons done with NJ-Come Away With Me lp, the KT 88s are superior in the context of my system and my listening preferences.
Many thanks for all your input/advise.
Happy listening
Pradeep

I wouldn't be a bit surprised if brand new KT88s sounded better than end-of-life 6550s, of ANY brand, in ANYONE'S system. Happy listening!