Gecophone Early Radio Help wanted

[mendipviews]

hummmmm the plot thickens, I had a look at the picture but the front is different where the tuning window is I have a multi position switch marked "volume control" and under that a four pin valve type socket marked reactance, they are both lettered like the other controls so I don't think its a home mod.
The two valves that are in it are both DE8LF as I managed to read the markings on the unknown one under a lamp.

Thanks for the help so far guys

Kind Regards
Luke