PJ,
Here is a quote from you:
"The design is optimized for the 2A3; to run a 45 the power supply voltage is dropped about 30 volts by increasing a power supply resistance. This resistor gets pretty hot! Significantly increasing the heat under the chassis is not recommended without changing the layout, and perhaps increasing the ventilation area - i.e. to do so reliably is not a minor alteration.
For conservative operation, I recommend running the 2A3 as if it were a 45 - much easier to do."
(The above is exerted from a January 2015 posting)
I think I'll avoid the major alterations and go for the Tucker 45