To update this thread. Over the winter, I fitted a period us model Blaupunkt (still using a standard surround as I need to still get some brown vinyl), also fitted an ipod interface using the pin connector on the back. Dont really use the stereo but when commuting to work and sat in traffic, it's good to have the option.
I also went through all the electrical connectors and cleaned them up. The following from Early S Man on Pelican worked a treat:
1. Remove your bulb holders one at a time and clean & polish both the Faston tab and the holder body with HD rubbing compound or metal polish ... until bright and shiny brass is all you can see. Clean the Faston connector at each bulb with vinegar and old toothbrush, then rinse with distilled water ... you should see slight 'pink' coloration of the copper in the brass alloy! Put a small amount of Dow Corning 4 or 111 Silicone Grease on the tab and Faston connector and reconnect.
2. Clean the ground tab and connector at each instrument and treat with silicone grease.
3. Replace the bulbs.
Bulbs are really bright now. I also did every other connector in this way, replacing if necessary.
Whilst I was doing this, I noticed that there was a rattle in the speed switch and opened it up and fond this:

(sorry for the poor pic!)
Talked to our resident electronic guru, Tim and he said no problem. I popped up and he soldered one back in, and tested the CDI, just while I was there, again no problem.
Whilst up there I also picked up a rubber bumper insert from James, as when I took my front over riders off I have a couple of holes in it.
Next was to get the distributor rebuilt, I sent it to H&H ignition, came back like this:
I had quite a few problems timing it afterwards. The problems can be read here:
http://www.ddk-online.com/phpBB2/viewtopic.php?t=34704
Once the problem had been tracked down, new gaskets were fitted and it went off to Bob’s.
Within 24 hours of the car going to Bob, I had a phone call to say the car is ready for collection. I asked what it made on the Dyno, I was expecting a little less than it made 3 years ago which was 154bhp, it didn’t, it made 160bhp!
Picked up the car last night, and the difference is really noticeable. It seems to pull much stronger and freer, had lots of fun on the way home! There is a little 'stumble' at around 3200, but I can live with that.
