No sure I can help as I don’t own these amps. However, you might find this Absolute Sound article useful. You can use lots of different tubes.
Svetlana SV811 tubes:
https://www.vivatubes.com/new-factory-tested-svetlana-sed-sv-811-3-high-power-vacuum-tube/
The SV811-10 are harder to find than the SV811-3