HI, Can anyone point me in the right direction, I need to get a new set of Ignition leads for my 85 K100RS
it still has the original ones in there and all corroded etc

Thanks

You can get NGK 5 ohm resistor caps of Ebay and get the leads made up by an ignition specialist. Or you can get them from EME https://www.euromotoelectrics.com/  Motor Works, Motobins or Munich BMW. Or try   http://www.hurricaneautomotive.com.au/custom-leads . I had a set made locally by an ignition specialist no longer there with NGK 5 ohm caps.
Regards Martin.

NGK has ready made plug wire sets for K bikes. You can get them from Euro Moto Electrics in the U.S. I'm pretty sure they are available someplace in Australia.

https://www.euromotoelectrics.com/category-s/1783.htm

If you decide to purchase the set from EME which I would recommend, I think they use Fedex for delivery to Oz and they are quite quick.  Previous orders have arrived on my doorstep in four to five days although delivery costs are not exactly cheap so order a a couple of spare filters or similar to provide a bit better value.  

On the other hand it recently took an order from Motobins over three weeks to arrive and that was only for a couple of cables.

I'm gonna take a hunch that by swapping out those 36 year old corroded leads, your ignition system is gonna love that decision 

It might be worth an Ohms test and a clean.

"It might be worth an Ohms test and a clean."

That would be my course of action before dropping $75+ on wires.  The plugs and their connectors are nice and cozy behind the cover, their only exposed spot is the connections at the coils.  

I'd take the plug wires off, clean them with dish soap, and air dry them well for a day or so.  Then give all the coil connections a shot of Deoxit before putting it all back together again.

I think 36 yrs for a set of plug wires is long enough. Its time to spend a few dollars on the old girl. If the coils test good, then that's what I would do.

I did the same thing for my 35 year old K100 this past winter. Plug wires can be fine at idle, but under a load they can start to break down.