I'm new to everything! Will this layout work?

[Probablynot]

Thanks for all the hints and encouragement - I'm taking note of them all!
Barry, your 'string-compasses' idea is good, but I'll probably cut a bit of scrap 2x1 in two and use a nut & bolt, plus a nail and a pencil, to create a real (giant) pair of compasses.
Mick (Bandit), you surprised me by suggesting I use drawing pins. D'you mean as a permanent way of fixing the track? Someone on Youtube was saying he pre-drilled holes in the flexi-track sleepers and used the ordinary track pins, which seems to me a more elegant way of doing it.

I made a start on the layout today, cutting an 8ft x 4ft plywood sheet into two shapes for the extra tables I need. It's excruciatingly slow work though - I'm still recovering from a pulmonary embolism that had me hospitalised less than a week ago. But I'm still hoping to have them constructed and in place by next weekend.

[Walkingthedog]

The drawing pins are temporary. Easier to move them about if necessary.

When you get round to using track pins may I recommend you buy the Gaugemaster version, far superior to other makes.

[Bandit Mick]

Sorry, I meant use drawings pins to temporarily keep track in the place you want it. If using pins to pin track in its final position, don’t use Hornsby ones as they are far too big.