I have had experiences of using Vintage E88CC and have been demonstrated some of the Valves mentioned above in devices that I own.
As a result I have acquired a selection of early 60's E88CC's from different producers
One Tube not mentioned and very worthy of being trialed is the early 60's Mullard CV 2493, these are rare to find, even thought not too long ago there was a Matched Pair for sale in the USA, for very fair money, if compared to present UK prices.
I also recently heard on two separate occasions an early 60's German produced E88CC in a CDP and the impact it had made on the device and within the HiFi system was extremely impressive .
The second listening was with a Group of attendees who had at an earlier date, been demonstrated the CDP with the stock valves. The response from the additional attendees were no different to my own, they were in awe of the presentation on offer, and very clear about the valuable impression being made in their appraisals.