Yes on the Siemens grey plate Cca being a great tube. As our our fellow audionaughts (nuts?) here have convinced me, I likely wouldn't notice much difference relative to the 1963 Siemens E188CCs that I'm currently running.
A bit more on the Voskhods that are on the way (they shipped within 5 hours of purchase!)...the link below if for the same tubes that I bought 4 of. I've learned that one dead give away for Voskhod 6n23p that were made for export are the nickel plated pins...for corrosion resistance (domestic market have steel pins). The export versions are said to be the best sounding. Can clearly see the ones in the link have the nickel plated pins.
https://www.ebay.com/itm/6N23P-ECC88-NATIONAL-VOSKHOD-TUBES-MATCHED-PAIR-NOS-NIB-E88CC-6DJ8-6922-197...
A bit more on the Voskhods that are on the way (they shipped within 5 hours of purchase!)...the link below if for the same tubes that I bought 4 of. I've learned that one dead give away for Voskhod 6n23p that were made for export are the nickel plated pins...for corrosion resistance (domestic market have steel pins). The export versions are said to be the best sounding. Can clearly see the ones in the link have the nickel plated pins.
https://www.ebay.com/itm/6N23P-ECC88-NATIONAL-VOSKHOD-TUBES-MATCHED-PAIR-NOS-NIB-E88CC-6DJ8-6922-197...