No socket for a stereo decoder.

But a decoder has been mounted nevertheless

No threaded hole to accept the frontmost screw, which was then just left out

And also lacking a threaded hole, the cooling fin for the external transistor just sits in with the wires

Martin

And here, right next to the fuse where the service manual for the Master 610 shows
no components, only holes, some components were obviously cut out

Martin

Might be a prototype of BeoMaster 900, since it says BeoMaster 900 on the front. Maybe you can slap a red label on the backside......  Is the Stereo lamp also in the radio?

Yes, the stereo lamp is present but it doesn't have a proper holder.
It's merely squeezed in and held by a rough piece of foam.
There's no hole through the chassis for the wires either.

Martin

I'd go for the red label:" Early sample. Not to be in accordance with specifications".

But all fun aside, it must be a prototype or it must be something that was put together by a handy technician.

I thought the early versions all had the grey coloured facia. Could this be a "bitsa" unit made up from different units. An early, maybe radiogram chassis and a later cabinet and dial.

It is actually the "grey" facia version as in the early version.
It's just that instead of the speakers two small plastic "fillers" with white stripes are
fitted at the sides of the dial. This is normal.

The solder joints are normal on the boards themselves but the solders of
the interconnecting leads look a bit "quick" made.

The speaker DIN sockets are not the usual types either.

Martin

Hey Martin! We're hanging on a cliff here!

Well, sorry but I have no more info on this. It's most likely an early test- or prototype unit as already suggested.
It has been put into storage now.

Martin