I did. That's why I surmised that any flippable numbers must end in 6 to be symmetrical.
so a number that contains all 0,1,6,8,9 must be 9xxxx6 to be flippable. so for any given 2nd digit, there are 5 possibilities, because the 5th digit must match, ie 90XX06, 91XX16, 96XX96, 98xx86, 99xx66. the middle two numbers must again match, so be either 00,11,69,88 or 96 5 possibilities for each.
Unless I'm missing something big my logic is sound.