I just found a cover that was close enough on Amazon, then got 10yds of 1/8" stretch cord to wrap around it.
and
I actually cut the straps that were on the cover off (as I discovered the 1st time, they're pretty useless - they loosened up and the wind destroyed the first cover I had). I then used 1 set of fasteners from those straps to connect
the 2 ends of the stretch cord (I didn't want to be tying/untying knots!)