The wheels on that, if 24" is correct, were probably marked Dunlop, 24x1 3/8. If you can't find the correct wheels, you may be able to fit 26" wheels --the mountain bike size rim, but with skinny tires. Assuming you find the fork, that is. Good luck with that!
700c or even a 29" rigid fork, layback seatpost, instant chopper...
