Probsub Rules Question - Surface Vessels Supplement Available?

[Mako]

Does anyone know R. Prescott, or A. Amos, of Dover, UK, who created/wrote the Probsub, nuclear submarine miniatures rules?

I'd like to get in touch with them, or to know if they ever published the follow-on rules supplement which was planned to add surface vessels to their rules, both as targets for the subs, and as anti-sub platforms for naval combat. 

The rules were published back around 1990, and they mentioned they hoped to publish the supplement shortly after the publication of their nuke sub vs. sub rules, but I don't recall ever seeing them.  Of course, it's entirely possible that they did, and I'm just unaware of them.

I'm also interested in rules for diesel-electric subs, and the more modern, AIP derivatives of those too, if anyone has come up with special house, or official rules for them too.