It is worth mentioning that I suspect that the Mayer that Howie has here wouldn’t sound especially like the current versions as quite different parts (for example Tango versus Lundahl etc). In other words, I recommend to be somewhat cautious in extrapolation. Not to say one wouldn’t prefer the original versions either!
The tango should be better than Lundahl, I have never compared just going by online babble. he has got the best of the tubes for the preamp.
For the phono he has got the better tubes Thomas himself preferred EC8020 but had to stop on those due to lack of availability so he moved to D3a (as he has himself written on DIY audio forum). The Western electric 437 Howie has are alternates to the EC8020 which is Thomas' favorite iDHT.
I haven't heard it as we only get to hear the D3a these days. It is the preamp that I think is great, the D3a phono is very good too but just that in phono space I like many. Jeroen also has the D3a next to his top of the line pass labs if someone wants to get notes.
Personally I haven't heard any kondo or audionote doing this level of nuance but there are differences in old kondo, new kondo, AN-J and AN-UK.