[JasonB]

Yes there are people who make bespoke tracks, but I wouldn't expect them to be cheap.

In the UK - https://www.thinkscalextricevents.co.uk/...yMenu.html
In France - https://sillage-racing.com/

But routers aren't too expensive, especially since a track only requires some slots to be cut, so you don't need anything approaching the top of the range. Also, routing isn't too difficult if you're reasonably handy as you would usually use a simple guide, ie a plank of wood for the straight sections, and a pinned curved material, or a compass arm for the corners. Small mistakes can easily be filled, and since MDF is reasonably cheap, any big mistakes aren't going to break the bank.

Mr Flippant sells a wood track routing kit which has some handy stuff https://www.ggaub.com/slots/wood.shtml

How a routed track might differ in design to a Scalextric track is obviously up to you. It could be very similar, but of course there are many more options available. You can choose the number of lanes you want, the lane widths, and the type of corners, and as you can see from the routed tracks you've picked out, you can have a much more "organic" looking layout. There is also a huge difference in smoothness when you're not clickety-clacking over a track joint every foot or so.

Since you've got a garage you could work in, I'd say it's definitely worth considering.