I have a similar vintage Autohelm, and my understanding is that I can retain the linear drive for use with a later control system. Cannot be certain, but after all it's only a 12V motor.
i'd like to fit one of the later intelligent control units which learn the yaw characteristics of the boat. Mine is not much use downwind and I've heard that the later units are much better.
All hearsay, so will be interested in more informed replies
The S1 is nearer equivalent to the old 6000 system. The linear drivein the S1 Saildrive version is quite a lot more powerful than the old 5000 version. AFAIK the old drive would be adequate (if it proved to be before, but if you had problems with downwind steering, it may be that the faster stronger response of the new linear drive will be as important as also having the gyro rated aided reaction system). (SI= non-gyro rate aided. S1(G) is the system with the gyro, but you are supposed to be able to add the gyro later (for extra money)
Hi - there's only one person who can really help - Dave Wellcome of Raymarine. The one and only guru who knows the products from an engineering point of view, and who has helped so many on the forum.
02392 693 611 extension 1614.
You will probably find he wrote the software and specced the hardware....
<hr width=100% size=1>Piers du Pré
http://www.dupre.co.uk
Sounds to me as though the drive will be fine but I am curious why you would want to source anything in the UK ? Check out Raymarines US web site for a refurbed (new style grey) 5000 control head. I bought one last year I think it was <$500. I am also in Florida.