[Mondial]

Why not try and get it working as is. From the look of the under chassis work, it appears that the person who did the mods knew what he was doing. He used shielded cable for the audio wiring to the volume control, and the filament wiring of the 6 volt tubes is done properly with twisted pairs instead of using the chassis as a ground return.

So its not exactly original, but its performance will probably be better than a stock 90. The mods appear to be to only the audio section and the 2A5 will give better audio with less AC hum than the 47.

I kind of like working on a set like this, because without trying to maintain originality, you can make further mods without feeling guilty about messing up a pristine original.