Useful info. here also
http://www.duckworksmagazine.com/03/col ... /part2.htm
And photos.

Spring update.
Lots of trial runs over the winter with bits of strings and various pulleys. Its now sorted and as advised its geared down with 2 pulleys on the engine connector which means its 2 full turns of the wheel lock to lock. The engine will now tilt up without the cables catching on anything.
I bought 6 U bolts (from 3i) which are great and secure and have 2 metal oval plates for extra reassurance. At the front the U bolts go through the hull rather than the previous half inch wood screws into a batten but because of the oval plate and a couple of cap nuts in chrome it looks fine.
The pulleys were from America as I wanted the Perco ones that have a 'snap' on the hook.

You do not have to suffer the cable steering on your boat. Mine has the same wheel, and it uses the common taper on all modern push pull steering helms such as Teleflex or Morse so it will fit on the shaft no sweat. That wheel is called an Attwood Flying Crest by the way, about 1962 vintage.

Advice please
My current Broom Rapier has its original wire and pulley steering which I will renew. The photo above was my previous PennCraft.

The setup is different to most advice on the web in that the cables terminate on the outboard i.e there are no pulleys on the outboard bracket and no attachment eyes back on the transom. Is this OK-? I presume it will make the steering more sensitive?

And there is no spring on the system- just a tensioning turnbuckle. I was going to add a spring- if so is the advice still just on the starboard side - and can it attach at the end of the cable where it attaches to the outboard?

My Yarecraft which is similar to your Broom has always had the cables directly onto the outboard (Evinrude 40HP) there are no holes or screws either side of the splashwell to suggest that it was ever different. I have a spring on either side of the cable which attach to the motor, so two springs. This set up has always worked well although it is of course heavier than the two pulley set up. I don't find it twitchy at all probably because its damped out by the heavier weight feel. At slow speeds i can still spin the steering from side to side easily when maneuvering. I guess another factor is the size of your wheel, a classic sized Attwood type will give you better leverage than a leather bound shirt button.