Waxoyl rustproofing and spray applicator (Barnard's Green WR14)

Nearly full 5litre can of Waxoyl and the sprayer that can be screwed directly to the can. In the days when cars rusted as soon as it rained, this is the stuff you squirted into the areas where rust might form in your car and was one way of preserving your wheels and squeaking past the next MOT. The Waxoyl is still liquid but I can't remember when I bought it. It's probably at least 20 years old and I don't know if its effectiveness will have been degraded by time.