If the dash light is annoying and the Cruse main switch is hard to get would it be possible to use a fog light switch as a Cruse main switch and its indicator light too ?

I might have to nick that idea! :D
Cruise wasn't an option on TD's so the indicator light is replaced by the glow plug light.
The Cruise switch position is a mirror image of the Mk1 foglamp switch position, so a foglamp switch should be easy to get hold of, and fairly simple to modify and fit.
It might be possible to pull an instrument binnacle apart and use the tell-tale graphic on the front of the foglamp switch.

That is what I'm considering, would need to be the front one as it latches where as the rear operates a relay somewhere.

So the main switch is a latching switch? That's easy then as there are a multitude of latching switches on the market!!
The collecting of parts got under way for me today as I won the interface module and cruse ecu on the bay for £13.50 :)

How's the cruise control mod going?

It's close, everything is wired up but I don't seem to be getting a speed signal so need to check some more of the wiring.

How is this project progressing? (Or not?)

It seems on a new throttle body I have that it came with the cruise actuator... so am wondering how easy it is to do :)

I connected it all up a few weeks ago and..................nothing.

I'm sure it's down to power supplies.

I wouldn't say it is easy to do, especially as it doesn't work yet.

To make it work you need a lot more than just the acuator.

I realise that :) but since I have the first bit I am wondering if its worth adding the rest... :)

Unless you find a doner in a scrappy you'll find the parts costs mount up. I've just spent £26 with Rimmers just to get the steering wheel switches so I can do similar in the MGF.

And to be honest it will be quicker to get an after market system like I have for the F.