For those of you making older sports and open wheeled cars that had bigger wheels Pendleslot has released a range of ~19" wire wheels.
These wheels are the same great quality as Pendle's other wire wheels. They work around $15-20 a pair depending on exchange rate and postage.
I am happy with them I think they are a good size and look right on the older cars.
If anyone is looking for even larger wheels they also offer a vintage wire wheel. These are a good size for older Scalextric cars like the Bentley and for those early German GP cars with the oversized wheels.
With the right tyre these would suit 1/24 scale cars as well.