@tonydennison Kentucky Radio made some excellent tubes. I had ‘50’s 12ax7 blackplates. They sound excellent but harder to fine and can be pricey. I prefer the RCA over them. Ken Rad made some pewter plates in the 50’s that are even better but I never had any. Ken Rad was bought by GE so GE 12ax7 grayplates from early 60’s are really nice and an exceptional value if cost is a concern.
The order of best impact for me would be the order you listed but all are important. Cheers!