Hi, everyone!

I've currently got my 1987 k100rt Ex-Police Bike apart replacing the rear main seal and, the 6 rivet output shaft.

Whilst I've got the whole bike apart I decided to inspect the clutch, however I'm not too entirely familiar with how dry clutches should look, as I'm more used to a wet clutch of your everyday motorcycle.

This is what my clutch currently looks like, it measures between 4.68 around the outside and 5.20 around the inside. Manual says service limit is 4.50, which is getting close-ish.

My question is do these pressure plates and friction plate look normal? I can see signs of scoring and wear, but I don't really know what I'm looking for. As a side note, the clutch seemed to be functioning normally when I used the bike last, and the clutch has not been contaminated by oil.

If you're that far in, I'd change the clutch anyway. Depending on abuse, it has maybe a few thousand miles left on it. As for the pressure plates; being an ex-police bike I'm not surprised that they're showing signs of localised overheating. As long as they're flat, they'll be okay. Whatever you do, be very, very careful not to bend the locator pins. They're quite soft and I can absolutely guarantee hours of fun trying to get everything re-aligned after you've bent them.

At this stage of stripdown it would be sensible to install a new clutch assembly,It would be a right pain in the bum to have to strip down again in a few months or miles,not cheap but good practice.

Your steel plates are dished and if you put a new pate in it will only grip on the outer edge and slip.
I would be putting a complete new pack in or leave it alone and it will probably give some more good service if treated with respect.
I have done it twice and neither bike has come back with clutch problems.

RicK G wrote:or leave it alone and it will probably give some more good service if treated with respect.

I'd go with this. Don't abuse it and fix it when it starts slipping.

Some police clutches (like those of traffic cops) take a lot of abuse since they routinely go from zero to really fast every time they need to chase down a speeder. Also, police don't have to pay for maintenance so them of them don't care how hard they are on a bike.

Change disc & plates. Even if you could cope with it like that you'll have to do it soon.
I know the bad treatments police bikes endure as I used to inflict them...
Don't forget to  apply specific  grease  (Staburags NBU 30 PTM or Optimol) on the shaft and disc teeth and, usually forgotten, on the red marks seen beneath (it's a R100 scheme but very similar to K100)
Parts must be cleaned before with no grease at all, then you can apply this grease diluted with trichloethylene (1:5) and let it dry before mounting.
No need to spread a thick layer of grease, it's not a pancake and the extra grease could be centrifuged on the plate!
This will give you a smooth one-finger clutch.

Awesome information guys, thanks for the help!

So I've pretty much come the conclusion that I'll be replacing the entire clutch.
I figure that there will never be a more opportune time, as the is now to swap it out easily.
The price of a new clutch does kill me a little, but I do like the piece of mind.
For those that are interested, this is the current state of my bike 

It doesn't show it on JBT's pic, but put some copper grease on the locating pins (marked 'rondelles' on the diagram). I have pulled a clutch that was a real bastard to get apart because the pins had corroded in. Needless to say, that was where I had the fun getting them all lined up again...

That picture looks about right - just a weekend away from being on the road again 

If I recall 5.5mm is the thickness of the disc when new, 4.5mm is the worn limit. 
I had clutch slipping one my 1985RT @ 101000kms which had a strange behaviour and took me some time to identify the problem. Clutch was never slipping when I was cruising until 100-120km/h. Once I had to cruise up to 160km/h for 20-25 minutes on 5th gear. After that I have entered city traffic and the clutch started slipping at 4th and 5th gear. 
I did that test again and again and the result was always the same.
Then I have stripped the clutch assembly. Plates were a bit better looking than yous with fewer discolourations ( high friction heat / slipping causes these ) and my clutch disc had left 4.6mm of material. 
Swapped the whole assembly due to plates (slight) warping , also swapped the Rear Main Seal ( old and dry ) and the o-ring. 
My advise would be to replace the whole Assembly with a heat/oil resistant clutch plate in the kit. It would be the last time you deal with the clutch for hundreds of happy km's 
Proper lube as mentioned, new clutch cable and setting and you're set!

Cheers