The mark you inflicted is not on the sensor Mike, but on the glass filter that sits in front of it. This is the part that is replaced in an IR conversion job so you are right, it'll be fine for the (potential) buyer's purpose.

You could narrow it down a bit if ou update your location in your profile. UK might as well read "The World, somewhere.". How about narrowing it down to a county, or a town even? We don't need full address and post code

You can download the PRA software from here, but I think you'll need an original version installed first.

I think the Pentax Remote Assistant software works only with the *istD, K10/20D bodies (two different s/w versions).

Isn't that called camouflage George.

It wouldn't slip through the barrier unnoticed if it was painted white.

Correct advice coming up:-

1: ALL Pentax badged flashes having a hot shoe will fit ALL Pentax cameras having a hot shoe.
2: The flashes in 1: above will work with the bodies in 1: above, with some limitations in some cases.
3: Specifically, your AF280T will work with your K10D, but will not use it's TTL capability because TTL is not supported by the K10D (only the *istD and *istDS (maybe the *istDS2 as well) are TTL compatible). You can use the AF280T in fully manual mode or one of the two auto modes. If you set the flash to Auto/TTL, it will ALWAYS fully discharge so you'll have to use trial and error, distance charts, or a flash meter to achieve correct exposure.

You'll have to wait at least 24 hours before I will even think about viewing it.

A link might be useful.

Not quite, in fact, not at all. They have the same number of elements and groups, but there, the similarity ends. The D-FA is almost half the weight of the FA which is a superb macro lens, one of my favourites.

You will not be disappointed, it's built like a tank, hence it's weight at 600 grammes.

An 'ideal' portrait lens for film would be about 85-100mm. The closest you have to producing the same field of view would be the 50mm 1:1.7 (75mm equiv) and the FA-28-70mm zoom. The 16-45mm + 1.7 T/C might give interesting results too.

There is much more to a lens than it's focal length to qualify it as a 'good portrait' lens though. If it's a bit soft wide open, more common with fast lenses, that's good too.