These are hard tires to find. I tried to find some when I had the Meyers Lynx minibike a couple years ago. Luckily another member on this site found one for me, at an extremely reasonable price. I did find a couple other ones but they were weather checked.
I have the Meyers Lynx back and it still has the BAD tire on it. I used the good one on my Heathkit Boonie for the front tire. I may pull it off from the Boonie and put it on the Lynx.