Hooray it's finally done!!!
Here it is outside the galvanisers just after I had finished assembling it. The nickel is still nice and shiny!
The loading ramps need a little adjustment as I forgot to account for the light board on the back. Not difficult to fix though. I towed it home, about a 40 minute drive, and it towed fine.
I need to replace the tyres as a matter of course before I use it to carry a car (they are the original caravan tyres and I don't know how old they are, although there is loads of tread on them, I want to change them as a precaution).
Here's what it cost me in total:
Chassis - £62 from ebay
Steel - £150 from ultimate steel, Cardiff
Nuts and bolts - £15 from FES, Cowbridge
Galvanising - £170 by Cardiff Galvanisers (very poor customer service - I will not be using them again)
Light board with 7m cable and fog lamp - £15 from ebay
Jockey wheel - £12 from ebay
Winch - £12 from ebay
So all totalled that's £446, bargain.
(the only parts not accounted for are the loading ramps, as I made these from materials I had in the garage already, and they were given to me for free, or bought as part of larger batch for another project)