MHDT Orchid or Lampizator Amber 3?

Decent machine shop could do it, only needs it if using 6SN7 or CV-181.

Good point.

Where did you source your  Shuguang CV-181-Z? It appears only the 181-T variant is available in the US.....other than getting direct from China on Ebay. It appears at least some prefer the Z vs T model tube.

Maybe this would work!

https://www.amazon.com/Shuguang-Treasure-CV181-Z-Replace-CV181-T/dp/B01EA3ME9W/ref=sr_1_1?keywords=Shuguang+Treasure+Cv181-z+Vacuum+Tube&qid=1581270385&s=musical-instruments&sr=1-1

Singles or pairs "Z" series little warmer: https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=CV-181-Z&_sacat=0&...

I think the question of whether a Z is better than a T variant is open for discussion and might depend on other system characteristics. Don Sachs, who builds very well-respected Preamps and buys a ton of tubes from China and uses them in his equipment has a great deal of experience with these new Chinese tubes. He advised me that he believes that the T variant is better than the Z variant. I think the description that the Z variant is warmer aligns with what Don has told me. I have no experience with either of these tubes. Just trying to say that It might not be a situation where the T tube is always better than the Z tube.