I know.....I probably need a good kicking for taking this on, and its probably getting a bit boring.....but I don't care ;¬)

Close inspection suggests someone has attempted to open her up and I suspect they failed, looks like an attempt has been made to remove the tuning dial that has resulted in the machined disc being detached, and some of the casing screws have been replaced in the wrong places, the cheese head allen screws normally holding the selector switches in place have been replaced with slotted screws and an allen screw is located to the rear.

The ebay seller advised that the unit was completely dead and therefore had removed the plug from the power cord, fair enough.

Removed the securing nut from the tuning spindle and following the application of some servisol and a couple of quite firm taps was able to draw out the damaged tuning wheel and dismantle the casing.

To my astonishment the internals look very nice indeed, I can see no footprints left by any previous repair technician, there did drop out a small pushbutton spiggot that has clearly come adrift from one of the keys which suggests a broken saddle somewhere within, but otherwise there are no signs of damage, burning or anything else.

The seller advised that the problem may be a blown internal fuse, wonder why he thought this, flipping the unit over and removing the fuse cover revealed one of the two 4A slow blow fuses was indeed blasted, the screws showed signs of removal. These fuses feed the primary windings of the transformer...if they are shorted out I fear the transformer may be goosed, could a high current in the secondary windings blow these fuses? I suspect not but some advice from Martin would be well recieved before I dive into this.............

A drastic short on a (powerful) secondary would cause a high primary current as well (that's where the power comes from).
Fit a new fuse.
Isolate the secondaries, gIve the transformer a creeping slow spin up on the variac and watch the primary current.
If it goes through the roof the transformer has shorted.
If  the transformer alone uses close to no power, check its secondary AC voltages.
If all is fine - check the loads with an ohmmeter - or fit them one by one and watch the current again as the mains is turned up slowly. 

Martin

By the time you've done this one I recon you'll be able to do them in your sleep! You might even have to change your username to Craig6000 😁

I think I may need counselling...........

Thanks for that Martin......had quite a time finding my way around the transformer, was a devil of a job removing the cover to get a good look at it all, it looks in really good shape actually, disconnected both 27v and 42v transformer outputs, dropped in two 3A slow blow (tried to err on the safe side) and with gritted teeth (don't have a variac, told my partner to put it on my Christmas list) powered up.....no load pops or sudden smell of burning shellac. with a heave of relief hooked up my fluke and measured 27v and 44v respectively......I think that puts the transformer in the clear.

Next I will pull out each bridge rectifier and measure up, I'm hoping for a short across one of them.