Made a bit of progress on this today.
I used the hull from a toddler's jet-ski toy for the main hull, a crows nest and a cargo door from an old pirate ship toy, and some plastic card and styrene ladders to make the basic shape.
I stuck the crow's nest on the back of the ship (I am using the blunt as the front, like Rey's speeder), and had to make a paper template to create a deck plate to cover it (as I'd already put the rails on - using the ladders, so it ws ticky to measure - textbook 'planning').
I drilled a hole in the bottom of the hull, and made a flight stand out of a 70s coaster and a thick cocktail stirrer.
The cocktail stirrer is held in place by a cunning bit of engineering
Realising this looked terrible. I decided to smooth off the interior of the cargo bay using a combination of plastic card and foam board.
When I installed the cargo bay, I decided to expose the hex like angles that sat under the deck of the pirate ship it originally belonged to. But because it stuck up so much, I've used some more styrene to smooth out the height difference a little. I also trimmed the nubs that create the hinge of the cargo door, so it can be easily removed and installed, if desired.
So this is what I ended up with (on and off stand). Blunt is the front! I intend to add some engines to the sides, similar to Luke's speeder in the original Star Wars, which should make it more obvious which is the business end - I'm imagining this is an industrial sized speeder
Finally, I finessed the ends of the ladders I'm using as rails, so they don't look so chunky. The rails will still need a lot more work, I think.