OK, well I've been continuing to play around with the various track pieces, but having tested quite few I've now decided to switch to printing ones with a view to creating a small layout. I've also changed to a different filament (Creality branded) which is also quite coincidentally nearer to the normal 'Tomy Blue Plastic Tracks' 🙂
Here's a couple of pics;
Some straights, 90 degree curves and some generic accessories (connnectors, 'on' ramps, buffers and column supports).

A pair of 'points' that could be used to create a siding or a passing loop

Finally here's picture of one of the original prints (cheap filament - Dark Blue) and one using the Creality filament - both were printed using the same settings... and illustrate how much difference filaments can make, both are standard PLA formulations, just one is better than the other...
