Here is a quote from one of the team involved in the project, dating from 2009
It last flew with two stage engines, and is configured as such internally. All the currently fitted systems, including radiators, engine controls and so on, are set up for the two stage engines.
When it was rescued from Panshangar, it was shipped to Hatfield, and parts were found to complete it externally. The cowlings are not original; some being cut down 2 stage type. The Spinners are Lancaster. The propellers were assembled from scrap parts. The engines were freshly inhibited, taken from stock somewhere, but are not associated with this aircraft.
In this configuration (and importantly, with this fuselage) it hasnt flown as E0234. It would therefore be wrong to take it back to 1940 specification - even if we could.
At present, we are considering if it would be possible to take it back to the configuration it was in when it last flew, which would be more appropriate for the airframe.
This is their raison d'etre and I neither agree nor disagree with it personally, it is what it is. At the end of the day the airframe belongs to the museum and the curator and those appointed to the project get to make a decision.