Never heard of anything in 15" in those sizes - even when 15's were in their heyday. Pirelli used to do a 285/50-15 which Robnell used in the early days.
The only one I could turn up was the 285/40-15 at Tyresales and Tempe Tyres, but out of stock and dare say permanently. Looks like a sprint car tyre though.
https://www.tyresales.com.au/search?...y=pricelowhigh
Yokohama 2854015 92W V141 | Tyres | Tempe Tyres