Thanks, McCreed

I've taken on board all of your suggestions and thoughts. Makes sense.

At this stage I'm going to go back, give everything another really good sanding and then have another go - you've kinda given my licence to do what I was wanting to do (ie several lighter, runnier applications). That approach resonates with me and I have no problem with having to do the process several times. Sandpaper is cheap and elbow grease is plentiful.

Cheers