This was described as a 'Dedicated Flash'. It's not, it's a standard automatic gun. You're a pro photographer, so you probably know this, but for the record dedicated flash guns interact with the camera digitally to provide TTL flash metering, this is a standard gun that requires the camera to be preset manually according to the scales on the rear of the unit only. The simple evidence for this is the hot shoe contacts being double pole only, typical dedicated flashes have as many as five, a minimum of three., the ground, the fire, and the digital communication.
The auto test appears to not be working correctly, whilst it seems that the gun is working reasonably well, the test indicator does not illuminate other than when the gun is fired. On other guns I've seen this indicator stays on for a few seconds to allow viewing, if this is not the case with this one then it's rare.
Alll of the following revolves around cleanliness and marks. No cleaning has been carried out, this is as they were received. In view of that external cleaning will remove most of the problems, may remove a particular concern with the mirror lens, but will certainly require dis-assembly for the remainder. The images were taken using a tungsten light, and/or a soft bounce flash, as direct flash exaggerates dust unfairly. The images have been resized only, no other corrections or re-touching, all are full frame taken on an Olympus E-20 through a 10+ dioptre close up lens.
This image shows surface dust. Looking inside the lens it would appear to be ok, I would say this is the best of the lenses, cleanliness wise.

Whilst this lens carries similar surface dust to the rest, there is a significant amount within the lens itself. This image is focussed on the inside surface of the rear lens element. Cleaning will require dis-assembly.

This too has dust inside it, in addition there is a mark dead centre of the rear element, I'm not sure if this is another fingerprint, or if it's abrasion damage, but you can just make out the mark in this image looking like a water mark, you can see the surface dust, and the softer looking particles of dust within.

As this is the lens type I really wanted to get back, this is the biggest concern of mine.
There are cleaning wipe marks on the front element, not a problem, but significantly there is what appears to be scratches. If you look closely at this image you can see the main mark, and the particle of dust/grit a little above the mark at the top end of it which caused it. The mark is consistent with a cleaning action. to the left and down slightly there is another longer but less pronounced mark. There are other marks of a similar nature on the remainder of the front element in lesser degrees of visibility.
The rear on the lens is fine, clean and unmarked, internally it is also fine.

The viewfinder has a significant amount of dust inside. This proved to be impossible to photograph in a way that isolated the internal dust, but in this image it's reasonable to say that half of the particles you can see here are within the finder. There is a slight difference in sharpness because of the depth of field between those on the outside, and those within, the external dust is also brighter.

This image speaks for itself. There's dust inside the whole of the rear of the camera, and you can see the dust trapped in the light trap for the camera back.

Again the potential for image quality problems is plain to see, the volume of dust itself, and the scratched take up spool and pressure roller shows potential for marking the emulsion of the film.

This kind of dust is common, and is usually easily removed, but I have a concern that if it gets to the shutter leaves that it could cause problems. I've not looked in detail, but I assume that the screen is removable, which may allow the viewfinder to be cleaned up somewhat too.

This was at the point when I rang you, so as already stated the external body areas of the lenses and cameras are fine, in good condition in fact for the age of the camera. Cleaning will resolve all of the dust problems here without difficulty. I did suspect as stated that most of this came from the newspaper packaging.
The only other issue is the cable release mentioned in your original description on racekites is not present.
Jerry