Hi Paul
I'm afraid your polisher just isn't going to do the job properly, i had one a few years ago, fine for polishing off polish residue but not good enough for compounding.
This is what you want
http://www.ebay.co.uk/itm/Car-Polish...0AAOSwkl5XecHE
For the compound use
Farecla G3 advanced compound followed by G6. These are both used dry although I always wet the cutting sponge first.
Using a proper compound polisher with the right compound is the only hope of getting a good finish.
If you want to bring your boot lid down to Egham sometime I can show you how it works and you can have a go before buying a polisher.